ArticlePDF AvailableLiterature Review

The Role of Diet and Exercise for the Maintenance of Fat-Free Mass and Resting Metabolic Rate During Weight Loss


Abstract and Figures

The incidence of obesity is increasing rapidly. Research efforts for effective treatment strategies still focus on diet and exercise programmes, the individual components of which have been investigated in intervention trials in order to determine the most effective recommendations for sustained changes in bodyweight. The foremost objective of a weight-loss trial has to be the reduction in body fat leading to a decrease in risk factors for metabolic syndrome. However, a concomitant decline in lean tissue can frequently be observed. Given that fat-free mass (FFM) represents a key determinant of the magnitude of resting metabolic rate (RMR), it follows that a decrease in lean tissue could hinder the progress of weight loss. Therefore, with respect to long-term effectiveness of weight-loss programmes, the loss of fat mass while maintaining FFM and RMR seems desirable. Diet intervention studies suggest spontaneous losses in bodyweight following low-fat diets, and current data on a reduction of the carbohydrate-to-protein ratio of the diet show promising outcomes. Exercise training is associated with an increase in energy expenditure, thus promoting changes in body composition and bodyweight while keeping dietary intake constant. The advantages of strength training may have greater implications than initially proposed with respect to decreasing percentage body fat and sustaining FFM. Research to date suggests that the addition of exercise programmes to dietary restriction can promote more favourable changes in body composition than diet or physical activity on its own. Moreover, recent research indicates that the macronutrient content of the energy-restricted diet may influence body compositional alterations following exercise regimens. Protein emerges as an important factor for the maintenance of or increase in FFM induced by exercise training. Changes in RMR can only partly be accounted for by alterations in respiring tissues, and other yet-undefined mechanisms have to be explored. These outcomes provide the scientific rationale to justify further randomised intervention trials on the synergies between diet and exercise approaches to yield favourable modifications in body composition.
Content may be subject to copyright.
Sports Med 2006; 36 (3): 239-262
2006 Adis Data Information BV. All rights reserved.
The Role of Diet and Exercise for the
Maintenance of Fat-Free Mass and
Resting Metabolic Rate During
Weight Loss
Petra Stiegler and Adam Cunliffe
Department of Human and Health Sciences, University of Westminster, London, UK
Abstract ....................................................................................239
1. Diet Intervention Studies ..................................................................241
1.1 Dietary Energy Restriction and Resting Metabolic Rate (RMR) ............................241
1.2 High-Carbohydrate, Low-Fat Diets .....................................................242
1.3 High-Protein Diets ....................................................................244
2. Exercise Intervention Studies ..............................................................246
2.1 Exercise and RMR ....................................................................246
2.2 Aerobic Exercise .....................................................................246
2.3 Resistance Exercise and Combined Aerobic and Resistance Exercise .....................249
3. Combined Diet and Exercise Intervention Studies ...........................................250
3.1 Dietary Energy Restriction and Aerobic Exercise .........................................250
3.2 Dietary Energy Restriction and Resistance Exercise ......................................254
3.3 Dietary Energy Restriction Combined with Aerobic and Resistance Exercise ...............255
4. Conclusion ..............................................................................257
The incidence of obesity is increasing rapidly. Research efforts for effective
treatment strategies still focus on diet and exercise programmes, the individual
components of which have been investigated in intervention trials in order to
determine the most effective recommendations for sustained changes in
bodyweight. The foremost objective of a weight-loss trial has to be the reduction
in body fat leading to a decrease in risk factors for metabolic syndrome. However,
a concomitant decline in lean tissue can frequently be observed. Given that
fat-free mass (FFM) represents a key determinant of the magnitude of resting
metabolic rate (RMR), it follows that a decrease in lean tissue could hinder the
progress of weight loss. Therefore, with respect to long-term effectiveness of
weight-loss programmes, the loss of fat mass while maintaining FFM and RMR
seems desirable.
240 Stiegler & Cunliffe
Diet intervention studies suggest spontaneous losses in bodyweight following
low-fat diets, and current data on a reduction of the carbohydrate-to-protein ratio
of the diet show promising outcomes. Exercise training is associated with an
increase in energy expenditure, thus promoting changes in body composition and
bodyweight while keeping dietary intake constant. The advantages of strength
training may have greater implications than initially proposed with respect to
decreasing percentage body fat and sustaining FFM. Research to date suggests
that the addition of exercise programmes to dietary restriction can promote more
favourable changes in body composition than diet or physical activity on its own.
Moreover, recent research indicates that the macronutrient content of the
energy-restricted diet may influence body compositional alterations following
exercise regimens. Protein emerges as an important factor for the maintenance of
or increase in FFM induced by exercise training. Changes in RMR can only partly
be accounted for by alterations in respiring tissues, and other yet-undefined
mechanisms have to be explored. These outcomes provide the scientific rationale
to justify further randomised intervention trials on the synergies between diet and
exercise approaches to yield favourable modifications in body composition.
The prevalence of obesity has risen enormously tion.
Over the past 2 decades, numerous interven-
over the past few decades. According to the World tion studies have examined strategies for the preven-
Health Report 2002,
obesity has increased 3-fold tion and treatment of obesity. Diet and exercise are
in some parts of North America, Eastern Europe, the still the key variables for both men and women to
Middle East, the Pacific Islands, Australasia and imbalance the energy equation in the direction of
China since 1980. Defined by a body mass index weight loss. An abundance of studies provide evi-
>30 kg/m
obesity has been associated with many dence of successful bodyweight reductions follow-
diseases, including some forms of cancer,
type 2 ing dietary restriction and physical activity.
diabetes mellitus,
coronary heart disease, However, in terms of the magnitude of change,
hypertension, dyslipidaemia, gallbladder disease, reductions in bodyweight are often below expecta-
sleep apnoea
and osteoarthritis.
Moreover, the majority of people are not
able to maintain the achieved losses and, over the
Factors underlying this epidemic are complex.
long term, weight regain is usually the case.
Although genetic susceptibility may play a role in
the development of excessive adiposity,
diet fac-
The reasons for the limited long-term effective-
tors, such as the availability of energy-dense food,
ness of conventional treatment strategies are di-
and the widespread reduction in physical activity
verse. The failure of changing lifestyle habits with
clearly make critical contributions.
Morbidity and
respect to dietary intake and regular physical activi-
mortality associated with obesity are substantial, but
ty during follow-up is well established.
can be effectively reduced following weight reduc-
behavioural issues are certainly the cornerstones,
weight maintenance appears to be antagonised by a
As early as 1975, a multi-factorial approach was reduction in resting metabolic rate (RMR). As the
used for the treatment of obesity, including dietary largest component of daily energy expenditure,
modification, exercise, psychotherapy and medica- RMR comprises approximately 60–70%. Fat-free
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
The Role of Diet and Exercise During Weight Loss 241
mass (FFM) is the main factor that accounts for the vention studies, exercise intervention studies and
magnitude of resting metabolism.
As a hetero- studies that have investigated the combined effects
geneous compartment, FFM consists of highly met- of diet and exercise for the treatment of obesity. The
abolically active muscle and organs and low- article covers well controlled, randomised clinical
metabolic rate tissues such as bone and connective trials conducted in subjects with at least a minor
[28] 1
Therefore, any diet or exercise interven- degree of over-fatness or overweight and where data
tions, which are capable of maintaining FFM or at on body compositional changes were provided. The
least attenuating its decline following weight loss, efficacy of the identified investigations was com-
could have significant effects on total energy bal- pared in terms of changes in bodyweight, fat mass,
ance. The residual variation in RMR seems to be FFM and RMR. As only a limited number of re-
related to a diversity of physiological parameters, search reports assessed energy expenditure, missing
such as thyroid hormones, leptin levels and sympa- data on RMR were not considered a criterion for
thetic nervous system activity. exclusion of the study. This article will conclude
with an evaluation of treatment strategies for obesi-
The foremost objective of a weight-loss trial has
ty, based on diet and exercise programmes and
to be the reduction in fat mass leading to a decrease
directions for future research will be discussed.
in risk factors for metabolic syndrome. However, an
accompanying loss in FFM can frequently be ob-
1. Diet Intervention Studies
served. Both with regard to a reduction in risk
factors and long-term weight maintenance the con-
tent of adipose tissue in the weight lost has to be
1.1 Dietary Energy Restriction and Resting
maximised, thus preserving FFM. It appears that
Metabolic Rate (RMR)
some dietary regimens induce a higher loss in FFM
than others, with the macronutrient composition and RMR is the energy expended by the active cell
the energy content of the diets having a major im- mass to maintain normal body functions at rest.
pact on the composition of the bodyweight lost.
There is evidence that RMR is largely dependent on
Another means by which a decline in bodyweight FFM.
Several intrinsic factors, which are be-
can be achieved while favourably modifying body yond the control of the individual, seem to account
composition with the maintenance of FFM is for the residual variation in RMR, including age,
through physical activity.
The ability of exer- sex, thyroid status
and genetic factors.
cise programmes to achieve these goals depends on
It is a well known fact that weight loss induced
the prescribed type and magnitude of exercise.
by dietary restriction is accompanied by a decline in
Therefore, as numerous studies show, a reduction in
RMR. A decrease in FFM mass most certainly has
RMR does not necessarily accompany a loss in FFM
considerable contribution to this effect
(figure 1).
and alterations in RMR might occur independent of
Concomitant neuroendocrine disturbances, such as
changes in muscle tissue.
Some studies have
alterations in leptin level,
thyroid status
reported that a low RMR is a determinant of weight
sympathetic nervous system activity
may further
gain, thus attenuating the decline in RMR is desira-
contribute to the decrease in RMR. This raises the
question as to whether the composition of the diet
Accordingly, the purpose of this review is to can modify physiological adaptations to energy re-
document recent (1990–2005) results of diet inter- striction, thus blunting the fall in RMR. The reduc-
1 Throughout this article, the terms ‘fat-free mass’ and ‘lean body mass’ are used interchangeably.
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
242 Stiegler & Cunliffe
and RMR has received little attention to date, sever-
al intervention studies have included those variables
in their outcome measurements.
1.2 High-Carbohydrate, Low-Fat Diets
There has been extensive research in the macro-
nutrient composition of the diet and its effect on
bodyweight reduction (table I). One popular ap-
proach within studies for the treatment of over-
weight entails altering the CHO to fat ratio in the
diet. The CARMEN (Carbohydrate Ratio Manage-
ment in European National diets) study, the largest
and most recent multicentre trial, tested the impact
of complex versus simple CHO in an ad libitum, fat-
reduced (by 10% of total energy) regimen in 398
Energy deficit
Fig. 1. Theoretical impact of energy restriction on fat mass (FM),
fat-free mass (FFM) and resting metabolic rate (RMR). Energy
deficit over a prolonged period of time induces a reduction in
bodyweight, which is based on a decrease in FM and, possibly,
FFM. These body compositional changes might be associated with
a decline in RMR.
overweight individuals. After 6 months, a signifi-
cant reduction in bodyweight and fat mass was
tion of adipose tissue during weight loss induces an
observed on both diets while sustaining FFM.
associated decline in the secretion of leptin.
This was further investigated in 45 overweight fe-
Changes in leptin level have been shown to predict
males. Similar to the CARMEN study, a low-fat,
changes in RMR. However, a positive association is
high-CHO diet led to a spontaneous decline in
still noticeable after adjusting for body composi-
bodyweight, which was independent of the gly-
indicating an effect of leptin on RMR inde-
caemic index of the foods consumed.
pendent of fat mass. Therefore, the maintenance of
the removal of a substantial amount of fat from the
leptin appears to be desirable for weight stability in
diet leads to a spontaneous decline in bodyweight.
the post-obese state.
There is some evidence for a
As shown in several other studies, the mechanism
positive association between carbohydrate (CHO)
appears to be due to the concomitant energy reduc-
consumption and leptin concentration during energy
Although some studies advocate the con-
suggesting an impact of the macronu-
sumption of foods with a low glycaemic index, this
trient content of the diet on energy expenditure.
was not confirmed in the two above-mentioned stud-
In order to prevent the decline in RMR, sus- ies.
In a recent review on high-CHO diets and
taining FFM emerges as an important aim. Studies energy balance, Brand-Miller et al.
claimed that
reveal that a protein intake sufficient to prevent foods that promote a high glycaemic response, such
negative nitrogen balance might be of great impor- as potatoes, breads and low-fat cereal products, tend
tance to lessen the decline in muscle mass
and to favour body fat gain. Another approach was ex-
energy expenditure (24-hour energy expenditure plored by randomly assigning 40 overweight wo-
and sleeping metabolic rate).
Thus, it is apparent men to an ad libitum, low-CHO diet or an energy-
that various factors associated with dietary composi- restricted, low-fat diet. After 4 months, the loss in
tion can modify the physiological adaptations to bodyweight and fat mass was greater in the low-
energy restriction. Although the potential effect of CHO group and reductions in FFM and RMR were
the macronutrient intake on the maintenance of FFM recorded. These results could not be accounted for
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
The Role of Diet and Exercise During Weight Loss 243
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
Table I. Diet intervention studies
Study Dietary intervention Subjects BMI Duration Bodyweight Fat mass FFM RMR
) (wk) (%) (%) (%) (%)
Saris et al.
CC: ad lib, low-fat, high complex 389 30.4 26 SC:
SC: ad lib, low-fat, high simple F, M CC:
C: control M C: NS
N: seasonal control group
Brehm et al.
LC: ad lib, low CHO (20 g/day) 40 F 33.2 16 LC:
6.7 LC:
LF: 30% fat, 55% CHO LF:
2.3 LF:
Sloth et al.
HGI: <30% fat, high GI 45 F 27.6 10 HGI:
1.6 HGI:
LGI: <30% fat, low GI LGI:
3.5 LGI:
Skov et al.
C: control diet (40% fat) 50 F, 15 M 30.4 26 HP:
HP: ad lib, 30% fat, 25% PRO HC:
HC: ad lib, 30% fat, 12% PRO
Baba et al.
80% of RMR, 30% fat 13 M 35.8 4 HP:
6.1 HP:
HP: 45% PRO HI HC:
HC: 12% PRO
Torbay et al.
80% of RMR, 30% fat 14 HI 35.1 4 HPHI:
15.7 NS HPHI:
HP: 45% PRO 13 NI NI:
6.6 NI:
Farnsworth et al.
70% TEE, 4wk E balance (30% 14 M 34.0 12
HP: 27% PRO 43 F
SP: 16% PRO
Luscombe-Marsh et 70% of TEE, 4wk E balance 32 F 34.0 12
HP: 29% fat, 34% PRO 15 M
SP: 45% fat, 18% PRO HI
Luscombe et al.
70% TEE, 4wk E balance (30% 10 M 34.1 12
HP: 27% PRO 26 F
SP: 16% PRO HI
Continued next pag
244 Stiegler & Cunliffe
by changes in components of energy expenditure or
intake through 3-day food records and most likely
represent underreporting.
Thus, although a low-
fat diet seems to induce a spontaneous loss in body
fat, this may be accompanied by reductions in FFM.
In addition, the current opinion on the impact of the
type of CHO on weight loss seems inconclusive.
1.3 High-Protein Diets
Recently, renewed interest was shown in whether
replacing some dietary CHO with protein may
favourably affect bodyweight and body composition
during energy restriction. Addressing this question,
Skov et al.
randomly assigned 60 overweight
subjects to a control diet or an ad libitum low-fat
diet, which was either high in protein or CHO. After
6 months, a clinically relevant loss of bodyweight
8.7 vs
5.0kg, p = 0.0002) and fat mass (
7.6 vs
4.3kg, p < 0.0001) was achieved on both low-fat
diets, which was greater in the high-protein than the
high-CHO group. The study design allowed the
participants to collect the foods from a shop set up
by the researchers. Therefore, between-group differ-
ences, such as a limited variety of foods shown to
influence bodyweight,
may have biased the re-
sults. However, the observed tendency was con-
firmed by a well controlled study in 24 overweight
women. The investigators examined the effects of
low-fat meals with CHO/protein ratios of 3.5 and
1.4. After 10 weeks, declines in bodyweight and fat
mass were similar across groups, but the participants
in the high-protein group achieved an elevated fat/
lean tissue loss (p < 0.05).
Moreover, a study in
13 hyperinsulinaemic obese men with normal fast-
ing plasma glucose levels showed similar effects
after 4 weeks on a hypo-energetic diet. A high intake
of protein was associated with 28% more weight
loss (
8.3 vs
6.0kg, p < 0.05) than the isocaloric
consumption of a diet high in CHO. It is possible
that this effect is partly derived from a significantly
greater loss of total body water in the high-protein
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
Table I. Contd
Study Dietary intervention Subjects BMI Duration Bodyweight Fat mass FFM RMR
) (wk) (%) (%) (%) (%)
Layman et al.
<1700 kcal/day 24 F 30.3 10
13.3 NS
HP: 30% PRO, 41% CHO
HC: 16% PRO, 58% CHO
a Significantly different from b, c and d at p < 0.05.
b Significantly different from a, c and d at p < 0.05.
c Significantly different from a, b and d at p < 0.05.
d Significantly different from a, b and c at p < 0.05.
ad lib = ad libitum; BMI = body mass index; C = control group; CC = diet high in complex carbohydrates; CHO = carbohydrate; E = energy; F = females; FFM = fat-free mass; GI =
glycaemic index; HC = high-carbohydrate diet; HCHI = high-carbohydrate diet, hyperinsulinaemic; HGI = high GI; HI = hyperinsulinaemic; HP = high-protein diet; HPHI = high-
protein diet, hyperinsulinaemic; LC = low-carbohydrate diet; LF = low-fat diet; LGI = low GI; M = males; N = no intervention; NI = normoinsulinaemic; NS = not statistically significant
(p > 0.05); PRO = protein; RMR = resting metabolic rate; SC = diet high in simple carbohydrates; SP = standard protein diet; TEE = total energy expenditure; = change.
The Role of Diet and Exercise During Weight Loss 245
compared with the high-CHO group.
In subjects ther CHO or fat may make some contribution. This
with normal insulin levels following the same proto- effect may also account for the reduced fall in
col, no major differences have been detected. How- 24-hour energy expenditure when maintaining the
ever, despite the comparable decline in lean tissue, protein content of an energy-restricted diet.
the high-protein diet was superior to the high-CHO thermore, compared with high-protein diets, hormo-
diet in maintaining RMR (p < 0.05),
in both nal responses associated with high-CHO diets may
hyperinsulinaemic and normoinsulinaemic partici- induce a series of physiological events favouring
catabolism of FFM. A rise in insulin following a
high intake of CHO promotes the uptake of glucose
In contrast, a study in 57 overweight subjects
and triacylglycerol in the liver and adipose tissue,
with slightly elevated insulin levels (>12 mU/L)
reduces glycogenolysis and lipolysis, thus sup-
failed to show an association between the protein
pressing the post-absorptive appearance of glucose
content of the diet and weight reduction after 12
and fatty acid. This triggers the release of counter-
weeks of energy restriction and 4 weeks of energy
regulatory hormones inducing catabolism of lean
balance. The results, however, indicated a preserva-
mass. Following the intake of a meal high in protein,
tion of lean mass during weight loss in the 43 female
less reliance on peripheral insulin actions and a
subjects (p = 0.02). The authors pointed out that the
delayed postprandial rate of disposal for amino acids
lack of an effect in the 14 male subjects may be due
appear to stabilise the glycaemic environment
to the small number participating in the study and a
and may conserve lean tissue. Moreover, the meta-
reported protein intake, which was sufficient to pre-
bolic role of leucine and the branched-chain amino
vent proteolysis in women, but not in men.
acids for muscle protein synthesis seems consistent
similar reduction in RMR was observed after the
with the conservation of FFM on high-protein di-
two diets, presumably in a subgroup (36 subjects) of
the above-mentioned study.
In a recent study
investigating energy restricted diets high in protein In one study, high-protein diets were investigated
or monounsaturated fat, no differences with respect under ad libitum conditions.
Subjects were re-
to body composition and RMR were found.
quired to cut out foods high in CHO. A greater
reduction in caloric intake due to the limitation in
The studies reviewed in this section indicate that
food choice rather than an effect of macronutrient
replacing some dietary CHO with protein might
composition may have facilitated the observed loss
favourably affect body compositional changes dur-
of bodyweight. This theory is supported by the
ing energy restriction compared with fat-restricted,
finding that the variety of sweets, snacks and CHO
high-CHO diets. The explanation for these observa-
consumed is positively associated with body fat-
tions, however, remains unclear. It is well estab-
Furthermore, more subtle aspects of palat-
lished that the utilisation of ingested nutrients for
ability of foods high in protein cannot be discounted.
energy is inversely related to the thermogenesis of
Nevertheless, several studies suggest that protein
food, a phenomenon associated with the energy cost
promotes satiety and reduces appetite when com-
of nutrient absorption, processing and storage.
pared with fat and CHO
and only a small
This loss of energy is highest for protein consisting
number oppose this view.
of 25–30% of the ingested energy, followed by CHO
with 6–8% and fat with only 2–3%.
Therefore, Therefore, in the light of recent data, high-protein
a higher thermogenic response following the intake hypocaloric diets may facilitate weight loss for over-
of protein compared with isocaloric preloads of ei- weight subjects while more lean tissue (and there-
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
246 Stiegler & Cunliffe
fore RMR) might be preserved. Moreover, a diet ing body fat. As importantly, weight loss due to
high in protein was superior to conventional diets in exercise may be associated with a retention of lean
improving insulin sensitivity
and no delete- body mass. Although weight reduction following
rious effects on blood pressure,
total cholesterol, physical activity is mainly brought about by the
and bone turnover
have energy expended during the exercise bout, addition-
been reported. However, according to Eisenstein et al mechanisms may increase resting metabolism,
detrimental impacts on bone health and renal thus further promoting energy imbalances. Given
disease can not be discounted as dietary protein the association between lean tissue and RMR, the
increases urinary calcium excretion. Evidence from most apparent impact of exercise training on resting
a study conducted by Kerstetter et al.
weighs metabolism is the ability to initiate skeletal muscle
against this hypothesis, as 80% of the protein-in- growth.
In addition, increases in energy expendi-
duced calciuria was compensated for by increased ture during the post-exercise recovery period (ex-
intestinal absorption of dietary calcium. In addition, cess post-exercise oxygen consumption) may induce
when substituting foods high in protein (e.g. dairy a short-term rise in metabolic rate for >24 hours.
products and nuts) for highly refined foods in the However, as recently reviewed, this effect might
grain and starch groups (e.g. bread, rice, cereals and only be noticeable following medium- to high-inten-
pasta) potential adverse effects of a high intake of sity exercise.
Despite a more rapid return to base-
protein may be reduced by other nutrients found in line levels in trained individuals,
regular exer-
the protein source (e.g. high amounts of calcium in cise bouts may promote small elevations in
milk or high potassium levels of legumes).
Further mechanisms, by which exercise
may increase metabolic rate, have yet to be fully
Based on the evidence noted in this section, the
elucidated, but may include uncoupled respira-
frequently recommended high-CHO, low-fat diets
protein turnover
and sympathetic ner-
have not always been associated with the greatest
vous system activity.
Therefore, the theoretical
loss in bodyweight. Complex and as yet incomplete-
effects of physical activity on changes in body com-
ly understood physiological processes associated
position are apparent. Nonetheless, with regard to
with a high intake of protein seem to facilitate
RMR, the literature to date is still inconclusive, as
reductions in body fat, with less declines in FFM
exercise training has also been associated with re-
and RMR. However, evidence is still scarce and
ductions in RMR.
As will be seen, the out-
further examinations are needed in order to clarify
comes of exercise intervention studies with respect
the relative merits of diets high in protein.
to body compositional alterations seem to be related
2. Exercise Intervention Studies
to the type of exercise, with intensity, frequency and
duration of the exercise bouts as limiting factors.
2.1 Exercise and RMR
2.2 Aerobic Exercise
Controlled trials on the effects of an increased
physical activity level as the primary intervention The design of exercise intervention studies varies
without diet modification provide the best way to in terms of the mode, frequency, intensity and dura-
determine exercise effects on weight, body compo- tion of exercise. Whereas total energy requirements
sition and RMR. An increase in physical activity rely on absolute exercise intensity, relative exercise
without changing energy intake can successfully intensity determines the contribution of fat and CHO
promote negative energy balance, thereby decreas- as fuels. It is well established that fat is the predomi-
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
The Role of Diet and Exercise During Weight Loss 247
nant source of energy during physical activity at low 16-month supervised trial with 31 men and 43 wo-
men. Aerobic exercise on 5 days a week significant-
to moderate intensities (<50% maximum oxygen
ly decreased bodyweight (
2.9kg) and fat mass
consumption [
]). A progressive decline of
4.8kg) in men. Interestingly, despite the consider-
fat oxidation in favour of CHO occurs with increas-
able amount of exercise performed, there were no
ing intensities (>50%
As oxygen sup-
body compositional changes from baseline in the
ply to the muscles is not sufficient at these intensi-
female participants, but the control group gained a
ties due to the limited capacity of the heart and
significant amount of weight (p < 0.05).
lungs, glucose is used as the only fuel that can be
the results of these studies show small, but signifi-
oxidised anaerobically.
Despite the relative de-
cant, reductions in body fat.
cline in fat oxidation with higher exercise intensi-
ties, the absolute quantity of fat oxidised may aug-
To determine, whether the intensity of exercise
ment as the amount of work performed increases.
alters outcomes with respect to bodyweight and
Thus, with the aim of utilisation of lipid stores and a
composition, Grediagin et al.
randomly assigned
high caloric expenditure, high-intensity exercise
12 untrained, moderately overweight women to ei-
might seem more beneficial. However, in the light
ther a high-intensity or a low-intensity exercise
of a low aerobic fitness and a bodily condition not
group. After 12 weeks of four-times weekly tread-
capable of high-intensity training in overweight and
mill training (with a duration designed to expend
obese patients, investigations into physical activity
300 kcal), no statistically significant differences
as a weight-loss tool have traditionally been based
were detected between the groups. In accordance, a
on low- to moderate-intensity exercise.
study set up by van Aggel-Leijssen et al.,
with a
similar design including a control group, failed to
van Aggel-Leijssen et al.
conducted a study in
show an effect on body composition. Twenty-four
21 pre-menopausal women with either lower- or
obese male volunteers trained according to a cycle
upper-body obesity (table II). All participants with
instead of a treadmill test protocol on only three
lower-body obesity were assigned to 12 weeks of a
occasions per week. Furthermore, RMR was slightly
low-intensity cycling programme and the women
lower after the 12-week intervention following the
with upper-body obesity were randomly divided
high-intensity training (
179 kcal/day, p < 0.05).
into an exercising and a control group. The study
outcomes failed to demonstrate any changes in body
The impact of exercise frequency and duration
composition and RMR across the groups. The same
was assessed in 22 sedentary, moderately obese
exercise modality was examined in the HERITAGE
females, who were randomly assigned to a continu-
Family Study,
a highly controlled multicentre
ous exercise group or an intermittent exercise group.
clinical trial, with a study population of 557 subjects
After 18 months, reductions in body fat (
2.1kg, p <
of various races and ages. The 20-week training
0.05) and weight (
1.5kg, p < 0.05) were only seen
programme consisted of exercise sessions on 3 days
in the continuous exercise group, whereas FFM was
per week with increasing intensity. The results sug-
unchanged in both.
Disparity in outcomes for
gested small, but statistically significant, reductions
weight loss may have been a consequence of differ-
in total body mass and fat mass and an increase in
ences in total weekly energy expenditure between
FFM, with no changes in RMR. In women,
the groups. To further investigate this, Sykes et
bodyweight did not change as the loss of fat mass
conducted a study in 30 overweight Sin-
equalled the gain in FFM. This was further investi-
gaporean women, who exercised at moderate inten-
gated in the Midwest Exercise Trial, a randomised sity on 2 and 5 days a week, respectively, with total
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
248 Stiegler & Cunliffe
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
Table II. Exercise intervention studies
Study Exercise intervention Subjects BMI Duration Bodyweight Fat FFM RMR
) (wk) (%) mass (%) (%)
van Aggel-Leijssen et al.
UB + LB: cycling, 40%
3 d/wk, EE = 13 F UB 32.7 12 NS NS NS NS
~250 kcal/d 8 F LB
UB-C: no intervention
Wilmore et al.
Cycling from 55%
30 min to 75% 299 F 25.4 20 M:
0.5 M:
+0.9 NS
50 min 3 d/wk 258 M F: NS F:
Donnelly et al.
and E: aerobic (primarily walking), from 55% to 70% 43 F 29.4 69 M:
5.1 M:
11.1 NS
Kirk et al.
20–45 min/d 5 d/wk 31 M F: NS
C: no intervention C: +3.6
C: +7.1
Grediagin et al.
LI: 50%
4 d/wk, EE = 300 kcal/d 12 F 25.0 12
HI: 80%
4 d/wk, EE = 300 kcal/d
van Aggel-Leijssen et al.
LI: 40%
3 d/wk, EE 350 kcal/d 24 F 31.8 12 NS NS NS HI:
HI: 70%
3 d/wk, EE 350 kcal/d LI: NS
C: no intervention
Donnelly et al.
CONT: walking 60–75%
30 min 3 d/wk 22 F 31.2 78 CONT:
1.8 CONT: NS
I: walking 2 × 15 min 5 d/wk I: NS
Sykes et al.
E1: treadmill + cycling 400 kcal 5 d/wk 30 F 23.8 8
4.2 NS
E2: treadmill + cycling 1000 kcal 2 d/wk
Schmitz et al.
R: resistance 50 min 2 d/wk 60 F 26.6 15 NS R:
R: +2.3
C: no intervention C: NS
Cullinen and Caldwell
R: resistance 45 min 2 d/wk 30 F 23.0 12 NS R:
8.1 R: +4.5 NS
C: no intervention C: NS C: NS
Byrne and Wilmore
R: resistance 4 d/wk 19 F 27.0 20 NS NS +4.0 R: +3.0
RW: resistance 4 d/wk + walking 20–40 min RW:
3 d/wk
C: no intervention
a Significantly different from b at p < 0.05.
b Significantly different from a at p < 0.05.
BMI = body mass index; C = control group; CONT = continuous exercise group; E = exercise group; E1 = exercise group one; E2 = exercise group two; EE = energy expenditure; F
= females; FFM = fat-free mass; HI = high-intensity exercise; I = intermittent exercise group; LB = lower-body obesity; LI = low-intensity exercise; M = males; NS = not statistically
significant (p > 0.05); R = resistance exercise group; RMR = resting metabolic rate; RW = resistance exercise and walking group; UB = upper-body obesity; UB-C = upper-body
obesity control group;
= maximal oxygen consumption; = change.
The Role of Diet and Exercise During Weight Loss 249
energy expenditure being the same. After 8 weeks, a were in those individuals that did a combination of
significant loss of bodyweight and body fat indicat-
resistance training and walking exercise, for whom
ed beneficial effects regardless of the training fre-
RMR declined (
53 kcal/day), despite an increase in
lean body mass. The authors suggested that the
In summary, prolonged, sub-maximal exercise
reduction in RMR was a result of heat acclimation as
may result in a small decline in bodyweight and fat
average monthly temperatures increased from the
mass. However, the magnitude of the change ap-
pre- to the post-training periods. Speakman and
pears to be less than expected and several exercise
discussed in a recent review a down-
protocols failed to reduce body fat. The impact of
regulation of uncoupling-protein 3 in muscle, en-
exercise intensity on FFM and RMR warrants fur-
hancing mechanical efficacy during physical activi-
ther evaluation.
ty, as a possible reason for a decline in RMR.
In summary, considering the amount of physical
2.3 Resistance Exercise and Combined
activity prescribed in the above-mentioned exercise
Aerobic and Resistance Exercise
intervention studies, the magnitude of the changes in
each of the variables was relatively small. With
The relatively small muscle mass usually used
respect to those studies that included measurements
during resistance exercise creates lower metabolic
of energy expenditure of the exercise bouts, theoret-
demands than aerobic exercise. Therefore, strength
ical losses in body fat could be calculated before-
training was considered to provide only minimal
hand. The observed reductions were frequently be-
stimulus to reduce body fat. However, as an impor-
low the expectations, and some exercise program-
tant benefit of resistance exercise, Walberg
mes failed to induce changes.
This raises the
ported in her review preliminary evidence that sug-
question of whether a compensation for the energy
gests weight training in favour of aerobic exercise to
deficits has occurred, either as a compensatory rise
preserve or increase FFM and RMR, while decreas-
in food intake, a decrease in spontaneous physical
ing body fat. Referring to experimental data, in a
activity, or both. Whereas some studies dispute a
recent study in 60 women aged between 30 and 50
reduction in spontaneous physical activity
years, 15 weeks of supervised strength training on 2
an increase in energy intake,
other studies
days per week resulted in a small but significant
provided strong evidence for at least partial compen-
increase in FFM (+0.89kg) and a similar loss in fat
satory trends with respect to habitual daily activi-
mass (
0.98kg) when compared with a control
and caloric consumption.
Some interest-
group. These body compositional changes were
ing patterns emerged from a recent study showing
maintained over 6 months through an unsupervised
that negative energy balance is compensated for
To investigate whether a combina-
more readily than surfeits and that this compensa-
tion of resistance training and walking was more
tion is more marked for changes in energy expendi-
beneficial than resistance exercise on its own, Byrne
ture, i.e. decreases in nonexercise activity, than in
and Wilmore
set up a study in 19 moderately
energy intake.
Thus, in free-living populations,
obese women. After 20 weeks, measurements of
this may be a key factor counteracting the expected
body composition indicated an increase in lean body
weight reduction. Furthermore, a less successful
mass in both exercise groups compared with a sed-
pattern of weight loss in women than in men has
entary control group, which was associated with an
been reported in two studies.
An increase in
elevation in RMR (+44 kcal/day) in the strength-
energy intake may have provoked these results.
trained subjects. The most striking results, however,
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
250 Stiegler & Cunliffe
With a high rate of restraint eaters,
dieting many recent studies support the beneficial role of a
women are more likely to allow for a greater food combination of the two.
intake when exercise has been performed.
ever, this notion remains controversial.
3.1 Dietary Energy Restriction and
data also lend credence to the idea that abdominal
Aerobic Exercise
adipose tissue, which is more pronounced in men, is
Over the past few decades, the focus of activity
better mobilised than gluteal adipose tissue as, for
programmes for obesity treatment has been on aero-
example, fat oxidation during exercise was only
bic exercise and the potential of this exercise type to
elevated in upper-body obese women when com-
improve outcomes has been repeatedly evaluated in
pared with participants with lower body obesity.
diet-exercise intervention studies (table III).
Nevertheless, there is insufficient evidence to gener-
As physical activity has been shown to promote
alise sex differences with respect to a loss in fat
favourable changes in body composition, the con-
mass induced by physical activity.
cept tested in some studies was as to whether exer-
The implications of the findings of strength train-
cise training may be a substitute for dietary restric-
ing for changes in body composition underline its
tion. Addressing this question, Frey-Hewitt et al.
potential to increase FFM and this requires further
randomly assigned 121 overweight men to 1 year of
energy restriction or engagement in walking/jogging
In summary, for exercise to be successful at
when compared with a control group. Although the
reducing body fat and increasing FFM, a considera-
reduction in bodyweight and fat mass in the dieters
ble number of regular exercise bouts need to be
was greater (p < 0.01) than in the exercise group,
performed. Regarding long-term effects of exercise
exercise training was superior to dieting with respect
on bodyweight and body composition, data are
to the maintenance of FFM. In the dieting subjects,
scarce and additional obesity intervention program-
FFM declined by 1.2kg and both absolute RMR
mes are required. However, considerable controver-
149 kcal/day) and RMR per kilogram FFM (
sy remains about the degree of the influence of
kcal/kg FFM) decreased (p < 0.05). An even more
exercise on RMR. While one study reported an
striking result was found in a 3-month study, with a
increase in RMR following strength training,
reduction in RMR (
247 kcal/day) after a hypo-
most studies reported no changes
and a decline in
caloric diet and an increase (202 kcal/day) following
RMR was detected in two intervention groups.
jogging on 3–5 days per week. When both groups
Thus, although exercise has the ability to increase
were evaluated simultaneously, alterations in RMR
FFM, an increase in RMR does not necessarily
were related to the changes in FFM. As the loss of
fat mass differed significantly between the groups, it
was pointed out that exercise alone might not bring
3. Combined Diet and Exercise
about the desired changes in bodyweight.
Intervention Studies
investigations have focused on the role of exercise
for body compositional changes when added to a
Inducing negative energy balance is the most hypocaloric diet. In an investigation in 20 obese
important aim of weight-loss programmes. Physical women, assigned to a very low-energy diet alone or
activity in conjunction with dietary energy restric- combined with modest exercise sessions, a greater
tion has been promoted as an important component reduction of fat mass (p < 0.05) was observed fol-
of successful weight-loss regimens. The results of lowing the exercise treatment, whereas declines in
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
The Role of Diet and Exercise During Weight Loss 251
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
Table III. Diet and exercise intervention studies
Study Dietary restriction Exercise Subjects BMI Duration Bodyweight Fat mass FFM RMR
) (wk) (%) (%) (%) (%)
Frey-Hewitt D:
300 to
500 kcal/d D, C: no exercise 121 M 27.3% BF 52 D:
et al.
E: no dietary restriction E: jogged 25 min 3 d/wk to 50 E:
C: no dietary restriction min 5 d/wk C: NS
Schwartz et D: 1200 kcal/d D: no exercise 31 M 29.4% BF 13 D:
E: no dietary restriction E: walking/jogging 7085% E:
2.3b E:
E: +6.7
HRR 40 min 35 d/wk
Kempen et Wk 14: formula, 478 kcal/d D: no exercise 20 F 32.0 8
9.1% D:
Wk 58: formula + food, 956 DE: aerobic 90 min 3 d/wk DE:
Hays et C: no dietary restriction C: no exercise 20 F, 14 M 30.9 12 D:
In the
D, DE: ad lib, 18% fat, 63% D: no exercise DE:
thigh: NS
CHO DE: aerobic 45 min 4 d/wk C: NS
Utter et C: no dietary restriction C: no exercise 91 F 33.0 12 C, E: NS
C, E: NS
E: no dietary restriction D: no exercise D, DE:
D, DE:
D, DE: 12001300 kcal/d DE, E: walking 6080%
45 min 5 d/wk
van Aggel- Wk 16: formula, 500 kcal/d DE: cycling, walking, aqua 40 M 32.3 10
Leijssen et Wk 710: formula + self- jogging 40%
, 60 min
selected foods 4 d/wk
D: no exercise
Brill et al.
12001400 kcal/d, <35g fat/ D: no exercise 56 F 34.0 12
d, ad lib high-fibre, low-fat, DE1: walking 30 min 5 d/wk
low-calorie foods DE2: walking 60 min 5 d/wk
Okura et Approx. 1130 kcal/d D: no exercise 90 F 29.3 14 D:
DW: walking 30 min 7 d/wk DW:
12.8 DW:
DA: aerobic dance 45 min 3 DA:
d/wk, DW:
EE = 1050 kcal/wk DA:
Continued next pag
252 Stiegler & Cunliffe
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
Table III. Contd
Study Dietary restriction Exercise Subjects BMI Duration Bodyweight Fat mass FFM RMR
) (wk) (%) (%) (%) (%)
Racette et ~75% of RMR, LF, LC: no exercise 23 F 34.1 12 LC:
compensated for EE of LFE, LCE: aerobic 6065% LF:
LFE, LCE > LF, kcal/d
45 min 3 d/wk LFE, LCE: 11.3 LC
LF, LFE: 60% CHO, 15% fat LF, LC: 8.9
LC, LCE: 25% CHO, 50%
Gornall and 812 kcal/day D: no exercise 20 F 28.8 4
DR: resistance 55 min 3 d/wk
Doi et al.
17% of EI Light resistance 25 min 7 d/ 17 M 25.9 12 C, S:
14.2 C:
2.1 S: +8.1
17% of EI + PRO wk S: NS C: NS
Demling and D: 80% of TEE D: no exercise 38 M 27% BF 12
2.6 D:
D: +0.6
DRC: 80% of TEE + casein DRC: resistance 4 d/wk DRC:
DRW: 80% of TEE + whey DRW: resistance 4 d/wk DRW:
Rice et
1000 kcal/d, fat <30% D: no exercise 29 M 32.7 16
27.4 D:
DA: 5085% HR
1960 DA: NS
min 5 d/wk DR: NS
DR: resistance 30 min 3 d/wk
Janssen et
1000 kcal/d, fat <30% D: no exercise 38 F 33.6 16
20.9 D:
DA: aerobic 5 d/wk DA, DR:
DR: resistance 3 d/wk NS
Geliebter et 70% of RMR D: no exercise 40 F, 25 M 41.1% BF 8
16.9 D:
DA: cycling 30 min 3 d/wk DA:
DR: resistance 60 min 3 d/wk DR:
Bryner et 800 kcal/d liquid formula, D: walking, biking or stair 17 F, 3M 35.4 12 D:
31.8 D:
8.0 D:
40% protein, 49% CHO climbing 1h 4 d/wk DR:
DR: NS DR: +3.6
DR: resistance 3 d/wk
Continued next pag
The Role of Diet and Exercise During Weight Loss 253
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
Table III. Contd
Study Dietary restriction Exercise Subjects BMI Duration Bodyweight Fat mass FFM RMR
) (wk) (%) (%) (%) (%)
Marks et C: no dietary restriction D: no exercise 44 F 29.4 20 C: 2.0
C: +2.2
D, DA, DR, DAR: ~1237 DA: cycling D, DA, DR, D, DA, DR,
kcal/d DR: resistance DAR: 5.2
DAR: both, 30 min 3 d/wk
Wadden et 900925 kcal/d (+ formula) D: no exercise 128 F 36.4 48
Wk 1819: + normal foods DA: aerobic (stepping)
Wk 20: 1250 kcal/d DR: resistance
Wk 2248: 1500 kcal/d DAR: both, 2040 min 3 d/wk
Kraemer et D, DA, DAR: ~1200 kcal/d C: no exercise 31 F 28.6 12
8.9 Approx.
23 NS NS
C: no dietary restriction D: no exercise
DA: aerobic 3 d/wk
DAR: aerobic + resistance
3050 min 3 d/wk
Svendsen et C: no dietary restriction C: no exercise 118 F 29.7 12 C: NS C: NS C: NS
D and DE: formula 1000 D: no exercise D, DE:
12.6 D:
DE: +11.5
kcal/d DE: aerobic + resistance DE:
11.5h 3 d/wk
Schlundt et LF: ad lib, high CHO Exercise 5 d/wk 49 M + F 31.8 1020 LF:
Lkcal: low-fat, low-calorie Lkcal:
a Significantly different from b and c at p < 0.05.
b Significantly different from a and c at p < 0.05.
c Significantly different from a and b at p < 0.05.
ad lib = ad libitum; approx. = approximately; BF = body fat; BFM = bone-free mass; BMI = body mass index; C = control group; CHO = carbohydrate; D = diet group; DA = diet and
aerobic exercise group; DAR = group following diet in combination with aerobic and resistance exercise; DE = diet and exercise group; DE1 = diet and exercise group one; DE2 =
diet and exercise group two; DR = diet and resistance exercise group; DRC = diet and resistance exercise group receiving casein supplement; DRW = diet and resistance exercise
group receiving whey supplement; DW = diet and walking exercise group; E = exercise group; EE = energy expenditure; EI = energy intake; F = females; FFM = fat-free mass;
= maximum heart rate; HRR = heart rate reserve; LC = low-carbohydrate diet group; LCE = low-carbohydrate diet and exercise group; LF = low-fat diet group; LFE = low-fat
diet and exercise group; Lkcal = low-calorie diet group; M = males; NS = not statistically significant (p > 0.05); PRO = protein; RMR = resting metabolic rate; S = diet group
receiving protein supplement; SMR = sleeping metabolic rate; TEE = total energy expenditure;
= maximal oxygen consumption; = change.
254 Stiegler & Cunliffe
FFM and sleeping metabolic rate were similar In summary, weight loss, and specifically fat
across groups.
loss, may be promoted by aerobic exercise alone and
during decreased energy intake, with a potential
In contrast to the above-mentioned outcomes,
attenuation of the depletion of FFM being of major
other investigators have been unable to confirm an
benefit. However, engagement in a considerable
increased fat loss induced by exercise training. In 91
amount of physical activity of at least moderate
obese women, brisk walking on its own, or as a diet
intensity is recommended, when exercise is per-
(1200–1500 kcal/day) plus exercise treatment
formed as a strategy to lessen body fat. The addition
showed no major impact on body mass and fat loss
of aerobic exercise during the reducing diet proved
when compared with a diet-only and a control
to be effective in preserving FFM in some studies.
These findings were confirmed in a recent
Changes in RMR did not necessarily appear to be
investigation by van Aggel-Leijssen et al.
attributable to changes in lean tissue mass.
ing a similar protocol in 40 obese men.
Some recent studies used an experimental ap-
3.2 Dietary Energy Restriction and
proach to delineate the relationship between exer-
Resistance Exercise
cise intensity and duration on bodyweight modifica-
tion during caloric restriction. Brill et al.
failed to
Recent findings have revealed a new perspective
show a positive effect of daily walking for 30 or 60
on physical activity as part of obesity intervention.
minutes with regard to alterations in body composi-
Resistance training shows promise as a means of
tion over a diet-only intervention in 56 overweight
losing bodyweight, while increasing or maintaining
women. However, the results of Okura et al.
muscle mass. With respect to lean body mass as a
oppose these findings. Daily walking for 30 minutes
major factor influencing RMR,
it is important to
was found to be associated with a greater decline in
look closely at the impact of strength training on a
fat mass (
6.6kg) over diet modification alone
successful pattern of weight reduction. A recent
5.0kg). A third group performed aerobic dance.
study investigating the effect of resistance exercise
This approach was superior to walking, due to a
on weight loss when added to a very-low calorie diet
greater loss of fat mass (
8.0kg) and the preserva-
(812 kcal/day) failed to indicate a suppressed de-
tion of fat- and bone-free mass.
cline in FFM and RMR after 4 weeks of interven-
It is likely that 40g of protein per day,
To assess both the effects of macronutrient com-
provided during severe energy restriction, was not
position and aerobic exercise on body composition,
sufficient to limit losses of skeletal muscle mass.
23 obese women were randomly assigned to an
Dietary protein is necessary to synthesise skeletal
energy restrictive diet either low in fat or CHO and
muscle and an increased intake may enhance nitro-
aerobic exercise or no exercise intervention in a 2 ×
gen retention and muscle hypertrophy. Therefore
2 factorial design. After 12 weeks, the decrease in
protein supplements are frequently used by strength
bodyweight was higher in the low-CHO group and
athletes to allow for accumulation and maintenance
the loss in fat mass tended to be enhanced following
of lean tissue.
exercise training despite food intake being adjusted
to the energy costs of the exercise sessions. No Doi et al.
investigated whether the ingestion
protective effect of exercise on RMR was found and of a protein supplement could prevent losses of FFM
RMR values decreased (
129 kcal/day) in all groups and, as a result, reductions in RMR in 17 overweight
to values lower than predicted from reductions in men participating in a 12-week weight-reduction
programme that consisted of both mild energy re-
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
The Role of Diet and Exercise During Weight Loss 255
striction (
17% of energy intake) and resistance of RMR) when compared with aerobic exercise in
exercise. The findings showed an increase in RMR
moderately obese subjects. These findings are in
expressed per kilogram bodyweight following the
agreement with those in a study of 20 subjects by
supplement intake, whereas the increase was not
Bryner et al.
that incorporated progressive inten-
significant (p = 0.07) when RMR was adjusted for
sive resistance training of high-volume and aerobic
changes in FFM. Recent research has also demon-
exercise of various modalities in conjunction with a
strated that the type of protein can markedly affect
very low-calorie diet. However, Geliebter et al.
body compositional changes induced by a hypo-
were unable to show a blunting in the decline in
caloric diet (80% of total daily energy expenditure)
RMR associated with a significant preservation of
plus resistance training. When a casein protein hy-
lean tissue following resistance exercise. Bryner et
drolysate was used, gains in lean mass were doubled
showed impressive results with a decrease in
(+4.1 vs +2.0kg) with a greater reduction in fat mass
lean body mass (
4.1kg) and RMR (
211 kcal/day)
7.0 vs
4.2kg) compared with a whey protein
in the group performing aerobic exercise, which was
Weight loss was similar across
not found when strength training was prescribed.
groups (
2.5kg) and in the diet control group, this
These outcomes could be explained by the high
was only from body fat (
2.5kg) with no change in
protein content of the diet of approximately 80 g/
day. Given the above-mentioned studies, convincing
data in support of either aerobic or resistance train-
3.3 Dietary Energy Restriction Combined
ing for weight loss and maintenance of muscle mass
with Aerobic and Resistance Exercise
are rare, but there was a tendency for a preservation
of lean tissue and RMR following strength exercise.
In the light of potential positive impacts of both
Several studies have examined whether a combi-
aerobic and strength programmes on body composi-
nation of the two exercise modalities may contribute
tion, some recent data provide insight into whether
to a more successful pattern of weight loss. Marks et
the effects are comparable. Rice et al.
investigated the effect of a hypocaloric diet
assigned 29 obese men to one of three 16-week
alone and together with resistance training, cycling
treatments, which consisted of a hypocaloric diet
or a combination of resistance training and cycling
alone or in combination with resistance exercise or
in a 20-week study in 44 overweight, inactive wo-
aerobic exercise, respectively. Whereas the reduc-
men. Mean reductions in fat mass and bodyweight
tions in weight (
12.4kg) and total adipose tissue
were comparable in the exercise groups to those
9.7kg) were not significantly different between
achieved by the diet controls and minimal changes
the three groups, skeletal muscle was only preserved
were observed in the non-diet control group. No
after the exercise training, independent of the mode,
major differences in FFM were detected from base-
compared with the diet-only group (
2.5kg). In wo-
line and between the groups. Nevertheless, only the
men following the same protocol, the effect of exer-
combination of diet, resistance training and aerobic
cise on maintaining lean body mass was less
exercise significantly lowered percentage body fat
In this study, the recorded changes in body
4.6%). Following a similar study design, Wadden
composition were comparable between the two ex-
et al.
failed to illustrate any positive impact of
ercise groups. In contrast, earlier work by Geliebter
exercise (strength training alone, aerobic training
et al.
demonstrated that only strength training
alone and as a combination) on body composition in
significantly attenuated the loss of lean tissue ac-
120 obese women when added to dietary restriction.
companying an energy-reduced formula diet (70%
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
256 Stiegler & Cunliffe
For participants in the aerobic condition, the reduc- than did subjects consuming a low-fat, ad libitum
tion in RMR was significantly blunted in week 24,
CHO diet. However, the authors pointed out that
but not at the end of the 48-week study period when
these results were related to a more reduced energy
compared with the strength condition. These results
intake in the low-calorie group.
are in accordance with those of Kraemer et al.,
From the above-mentioned studies it becomes
who examined the effects of diet alone and diet
clear that a combination of modest caloric restriction
combined with endurance exercise or endurance
and physical training of different modes is prefera-
plus heavy-resistance exercise in 31 overweight wo-
ble over dietary modification alone to induce fa-
men. After 12 weeks, similar reductions in body
vourable changes in body composition accompany-
mass (between
6.2 and
7.0kg) were demonstrated
ing weight loss. However, the reduction in
across the three treatment conditions, but without
bodyweight and the changes in body composition
changes in FFM and RMR.
induced by exercise training seem in many cases to
However, in another 12-week study in 118 over-
be less than expected, and several studies failed to
weight postmenopausal women, the addition of
report significant benefits of exercise. The lack of an
combined aerobic and resistance exercise to an ener-
impact of exercise training on body composition
gy-restrictive diet (1000 kcal/day) led to a greater
may be the prescribed amount of exercise not being
reduction in body fat (
9.6 vs
7.8kg) and a preser-
sufficient with respect to the frequency and duration
vation of FFM in the exercising group compared
of the exercise bout and from the investigated stud-
with the diet-alone treatment. Furthermore, an in-
ies, no clear line of evidence seems to emerge in
crease in RMR per kilogram bodyweight reached
terms of the minimum amount of exercise required
statistical significance in the diet-plus-exercise
for successful outcomes. In addition, to date no
group when compared with the control group.
intervention studies in overweight subjects have
However, this would not be surprising given that the
been done providing insight into the long-term ef-
decrease in bodyweight consisted of fat, not lean
fects of exercise programmes. Nevertheless, several
mass. From these studies in overweight and obese
lines of evidence suggest that resistance exercise
populations, it seems obvious that exercise training
may be preferable in terms of preserving FFM over
can reduce the loss in FFM during energy restric-
aerobic training and this type of exercise should be
tion. Another study showed that an individualised,
explored, especially in patients that did not succeed
more concentrated exercise protocol offers better
with aerobic exercise programmes. In addition, al-
overall results in terms of physical fitness and moti-
though training at higher intensities seemed to pro-
vation to subsequent physical activity (despite simi-
duce better results, long-term compliance needs to
lar results in terms of weight reduction).
be evaluated and constant monitoring of the exercis-
ing patient has to be ensured. With respect to the
Only one study has addressed the question as to
energy-restricted diet, there seems to be evidence
whether the effectiveness of a physical activity pro-
for protein intake as a limiting factor for mainte-
gramme with respect to changes in body composi-
nance and/or augmentation of FFM. Furthermore,
tion depends on the type of the prescribed, energy-
although only well controlled studies have been
restricted diet. In a 16- to 20-week programme with
included in this review, compensatory behaviour,
at least five exercise sessions per week, 60 subjects
such as reductions in non-exercise physical activity
consuming a low-calorie diet lost significantly more
and increases in food intake cannot be completely
weight, with a greater decline in body fat (
6.6 vs
ruled out in free-living subjects. A discrepancy be-
2.7kg) [and similar reductions in FFM and RMR],
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
The Role of Diet and Exercise During Weight Loss 257
tween self-reported and actual energy intake and Therefore, the juxtaposition of the energy restriction
and exercise treatment adds a layer of considerable
self-reported and actual physical activity in obese
complexity to measuring and understanding the re-
subjects is well established,
with the degree of
sponses recorded in RMR. Furthermore, the time of
under-/over-reporting being related to bodyweight.
measuring of RMR relative to the termination of the
As several studies required the subjects to keep daily
last exercise bout is important, because long-term
diet records for the duration of the study, while
excess post-exercise oxygen consumption events
regular dietary advice was provided,
may last for up to 36–48 hours.
accuracies of dietary histories may also have biased
there is no clear evidence for the alteration of RMR
some study outcomes. Moreover, although all the
by exercise. However, dietary restriction results in
assessed studies had recruited subjects with at least a
loss of lean tissue; the findings of several studies
minor degree of over-fatness, body fat of partici-
have demonstrated that the reduction in RMR can be
pants differed between studies. This appears to be
blunted via physical activity, specifically resistance
important, as a role of the body fat content for
changes in body composition induced by nutrition
Apart from changes in body composition, exer-
and exercise has been reported. Forbes
cise has been shown to increase insulin sensitivi-
evidence that lean body mass was a function of body
cardiovascular fitness
and fat oxida-
fat. Thus, the loss of FFM per unit of weight loss
In addition, abdominal fat can be re-
will be higher in those subjects with a lower initial
duced independent of significant changes in body
relative body fat content. These differences could
Moreover, increases in lifestyle ac-
confound the results when comparing studies with
tivity may also be promoted
and exercise is
participants with different body fatness.
associated with improvements in mood.
Another purpose of this review was to compare
fore (for a successful study outcome), exercise train-
intervention studies with respect to changes in
ing appears to be a beneficial if not substantial
RMR. However, only a few studies have examined
addition to diet modification.
RMR and these have produced equivocal findings.
Despite the well known association between FFM
4. Conclusion
and RMR, an offset in the decline in FFM following
weight loss appears not to necessarily parallel a
A rapidly growing body of evidence supports the
reduction in RMR and vice versa. A possible expla-
opinion that dietary recommendations beyond the
nation is that length and intensity of the exercise
generally advised reduction in fat intake should be
programme were not sufficient to cause a continued
considered for weight loss and long-term weight
disruption of metabolism or a growth of lean tissue.
sustenance. Several studies lend credence to the idea
Metabolically active compounds include FFM and
that diets high in fibre and with a low glycaemic
internal organs. Small changes in FFM my not be
index are successful at producing and, more impor-
sufficient to impact RMR. On the other hand, exer-
tantly, maintaining weight loss, which is due to a
cise training may influence RMR independent of
reduction in energy intake and hormonal responses
changes in body composition.
Increases in
associated with a blunted rise in blood glucose.
protein turnover associated with resistance training
Furthermore, potential benefits of diets high in pro-
regimens may contribute to elevations of metabolic
tein (between 25% and 30% of total energy intake)
However, the negative energy balance in-
are emerging, although scientific data with respect
duced by dietary limitation may offset this effect.
to enhanced losses of fat mass and sustained muscle
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
258 Stiegler & Cunliffe
tissue are still inconclusive. Long-term interven- Acknowledgements
tions are required to clarify these issues.
Support for the preparation of this manuscript was provid-
Evaluation of both aerobic and strength training
ed by the School of Biosciences, University of Westminster.
The authors have no conflicts of interest that are directly
for treatment of overweight indicates that higher
relevant to the content of this review.
intensities may bring about more favourable
changes in body composition. However, this may be
difficult to realise with respect to low cardiovascular
1. World Health Organization. The world health report 2002:
fitness in severely obese subjects. While the find-
reducing risks, promoting health life. Geneva: World Health
Organization, 2002
ings for resistance exercise show promising out-
2. World Health Organization. Technical report series (TRS):
comes with respect to changes in body composition
obesity – preventing and managing the global epidemic; 1997
Jun 3-5; Geneva. Geneva: World Health Organization, 1998.
and maintaining RMR, many studies have method-
Report no.: 894
ological limitations and/or results that are somewhat
3. Michaud DS, Giovannucci E, Willett WC, et al. Physical activi-
ty, obesity, height, and the risk of pancreatic cancer. JAMA
equivocal. It seems, therefore, that further research
2001; 286 (8): 921-9
in this area is required to clarify the most efficacious
4. Hu FB, Manson JE, Stampfer MJ, et al. Diet, lifestyle, and the
risk of type 2 diabetes mellitus in women. N Engl J Med 2001;
type of intervention with respect to exercise modali-
345 (11): 790-7
ty and dietary modification. Furthermore, the rela-
5. Rexrode KM, Hennekens CH, Willett WC, et al. A prospective
study of body mass index, weight change, and risk of stroke in
tionship between such interventions, body composi-
women. JAMA 1997; 277 (19): 1539-45
tion and energy balance requires a firm quantitative
6. Pisunyer FX. Medical hazards of obesity. Ann Intern Med 1993;
119 (7): 655-60
base from which advice may be given. Regarding
7. March LM, Bagga H. Epidemiology of osteoarthritis in Austra-
the serious problem of poor patient compliance with
lia. Med J Aust 2004; 180 (5 Suppl.): S6-10
8. Nieters A, Becker N, Linseisen J. Polymorphisms in candidate
exercise programmes, physical activity prescrip-
obesity genes and their interaction with dietary intake of n-6
tions, which would require the least effort while still
polyunsaturated fatty acids affect obesity risk in a sub-sample
of the EPIC-Heidelberg cohort. Eur J Nutr 2002; 41 (5):
producing the desired reductions in total body fat
warrant further evaluation. Recent research, howev-
9. Bouchard C, Tremblay A. Genetic influences on the response of
body fat and fat distribution to positive and negative energy
er, indicates that diet-exercise synergistic effects
balances in human identical twins. J Nutr 1997; 127: S943-7
may be significant in inducing negative energy bal-
10. Peters JC, Wyatt HR, Donahoo WT, et al. From instinct to
intellect: the challenge of maintaining healthy weight in the
ance. Thus, clearly the macronutrient composition
modern world. Obes Rev 2002; 3 (2): 69-74
of the diet is important and in this respect the role of
11. Mazansky H. A review of obesity and its management in 263
cases. S Afr Med J 1975; 49 (47): 1955-62
dietary protein is of considerable interest. For exam-
12. Saris WHM, Astrup A, Prentice AM, et al. Randomized con-
ple, in addition to its relatively high thermogenic
trolled trial of changes in dietary carbohydrate/fat ratio and
simple vs complex carbohydrates on body weight and blood
effect, some research suggests protein may attenuate
lipids: the CARMEN study. Int J Obes 2000; 24 (10): 1310-8
the muscle decline, which usually accompanies en-
13. Poppitt SD, Keogh GF, Prentice AM, et al. Long-term effects of
ad libitum low-fat, high-carbohydrate diets on body weight
ergy restriction. Therefore, in the light of the recent
and serum lipids in overweight subjects with metabolic syn-
data, the debate remains open and further well con-
drome. Am J Clin Nutr 2002; 75 (1): 11-20
trolled studies are required with respect to the com- 14. Meckling KA, Gauthier M, Grubb R, et al. Effects of a hypo-
caloric, low-carbohydrate diet on weight loss, blood lipids,
bined effects and the synergies and antagonisms that
blood pressure, glucose tolerance, and body composition in
free-living overweight women. Can J Physiol Pharmacol 2002;
exist between diet and exercise in relation to produc-
80 (11): 1095-105
ing desired changes in body composition and main-
15. Glass JN, Miller WC, Szymanski LM, et al. Physiological
responses to weight-loss intervention in inactive obese Afri-
taining elevations of metabolic rate.
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
The Role of Diet and Exercise During Weight Loss 259
can-American and Caucasian women. J Sports Med Phys during the early phase of a weight-reducing program in healthy
Fitness 2002; 42 (1): 56-64 humans. J Nutr Biochem 2003; 14 (9): 541-9
32. Belko AZ, Vanloan M, Barbieri TF, et al. Diet, exercise, weight-
16. van Aggel-Leijssen DPC, Saris WHM, Hul GB, et al. Short-
loss, and energy-expenditure in moderately overweight wo-
term effects of weight loss with or without low-intensity
men. Int J Obes 1987; 11 (2): 93-104
exercise training on fat metabolism in obese men. Am J Clin
Nutr 2001; 73 (3): 523-31
33. Schwartz RS, Jaeger LF, Veith RC, et al. The effect of diet or
exercise on plasma norepinephrine kinetics in moderately
17. Brill JB, Perry AC, Parker L, et al. Dose-response effect of
obese young men. Int J Obes 1990; 14 (1): 1-11
walking exercise on weight loss: how much is enough? Int J
34. van Aggel-Leijssen DP, Saris WH, Hul GB, et al. Long-term
Obes 2002; 26 (11): 1484-93
effects of low-intensity exercise training on fat metabolism in
18. Utter AC, Nieman DC, Shannonhouse EM, et al. Influence of
weight-reduced obese men. Metabolism 2002; 51 (8): 1003-10
diet and/or exercise on body composition and cardiorespirato-
35. Torbay N, Baba NH, Sawaya S, et al. High protein vs high
ry fitness in obese women. Int J Sport Nutr 1998; 8 (3): 213-22
carbohydrate hypoenergetic diet in treatment of obese
19. Borg P, Kukkonen-Harjula K, Fogelholm M, et al. Effects of
normoinsulinemic and hyperinsulinemic subjects. Nutr Res
walking or resistance training on weight loss maintenance in
2002; 22 (5): 587-98
obese, middle-aged men: a randomized trial. Int J Obes 2002;
36. Deriaz O, Fournier G, Tremblay A, et al. Lean-body-mass
26 (5): 676-83
composition and resting energy-expenditure before and after
20. Leslie WS, Lean MEJ, Baillie HM, et al. Weight management: a
long-term overfeeding. Am J Clin Nutr 1992; 56 (5): 840-7
comparison of existing dietary approaches in a work-site set-
37. Bitar A, Fellmann N, Vernet J, et al. Variations and determi-
ting. Int J Obes 2002; 26 (11): 1469-75
nants of energy expenditure as measured by whole-body indi-
21. Byrne NM, Weinsier RL, Hunter GR, et al. Influence of distri-
rect calorimetry during puberty and adolescence. Am J Clin
bution of lean body mass on resting metabolic rate after weight
Nutr 1999; 69 (6): 1209-16
loss and weight regain: comparison of responses in white and
38. Sparti A, DeLany JP, de la Bretonne JA, et al. Relationship
black women. Am J Clin Nutr 2003; 77 (6): 1368-73
between resting metabolic rate and the composition of the fat-
22. Gorin AA, Phelan S, Wing RR, et al. Promoting long-term
free mass. Metabolsim 1997; 46 (10): 1225-30
weight control: does dieting consistency matter? Int J Obes
39. Freake HC, Oppenheimer JH. Thermogenesis and thyroid-func-
2004; 28 (2): 278-81
tion. Annu Rev Nutr 1995; 15: 263-91
23. Leser MS, Yanovski SZ, Yanovski JA. A low-fat intake and
40. Astrup A, Toubro S, Dalgaard LT, et al. Impact of the v/v 55
greater activity level are associated with lower weight regain 3
polymorphism of the uncoupling protein 2 gene on 24-h ener-
years after completing a very-low-calorie diet. J Am Diet
gy expenditure and substrate oxidation. Int J Obes 1999; 23
Assoc 2002; 102 (9): 1252-6
(10): 1030-4
24. Tataranni PA, Harper IT, Snitker S, et al. Body weight gain in
41. Menozzi R, Bondi M, Baldini A, et al. Resting metabolic rate,
free-living Pima Indians: effect of energy intake vs expendi-
fat-free mass and catecholamine excretion during weight loss
ture. Int J Obes 2003; 27 (12): 1578-83
in female obese patients. Br J Nutr 2000; 84 (4): 515-20
25. Ravussin E, Lillioja S, Knowler WC, et al. Reduced rate of
42. Doucet E, St Pierre S, Almeras N, et al. Changes in energy
energy-expenditure as a risk factor for body-weight gain. N
expenditure and substrate oxidation resulting from weight loss
Engl J Med 1988; 318 (8): 467-72
in obese men and women: is there an important contribution of
26. Seidell JC, Muller DC, Sorkin JD, et al. Fasting respiratory
leptin? J Clin Endocrinol Metab 2000; 85 (4): 1550-6
exchange ratio and resting metabolic-rate as predictors of
43. Harper M-E, Dent R, Monemdjou S, et al. Decreased mitochon-
weight-gain: the Baltimore Longitudinal study on aging. Int J
drial proton leak and reduced expression of uncoupling protein
Obes 1992; 16 (9): 667-74
3 in skeletal muscle of obese diet-resistant women. Diabetes
27. Muller MJ, Grund A, Krause H, et al. Determinants of fat mass
2002; 51 (8): 2459-66
in prepubertal children. Br J Nutr 2002; 88 (5): 545-54
44. Pelletier C, Doucet E, Imbeault P, et al. Associations between
28. Muller MJ, Bosy-Westphal A, Kutzner D, et al. Metabolically
weight loss-induced changes in plasma organochlorine con-
active components of fat-free mass and resting energy expen-
centrations, serum T3 concentration, and resting metabolic
diture in humans: recent lessons from imaging technologies.
rate. Toxicol Sci 2002; 67 (1): 46-51
Obes Rev 2002; 3 (2): 113-22
45. Rosenbaum M, Hirsch J, Murphy E, et al. Effects of changes in
29. Layman DK, Boileau RA, Erickson DJ, et al. A reduced ratio of
body weight on carbohydrate metabolism, catecholamine ex-
dietary carbohydrate to protein improves body composition
cretion, and thyroid function. Am J Clin Nutr 2000; 71 (6):
and blood lipid profiles during weight loss in adult women. J
Nutr 2003; 133 (2): 411-7
46. Sandoval DA, Davis SN. Leptin: metabolic control and regula-
tion. J Diabetes Complications 2003; 17 (2): 108-13
30. Farnsworth E, Luscombe ND, Noakes M, et al. Effect of a high-
protein, energy-restricted diet on body composition, glycemic
47. Filozof CM, Murua C, Sanchez MP, et al. Low plasma leptin
control, and lipid concentrations in overweight and obese
concentration and low rates of fat oxidation in weight-stable
hyperinsulinemic men and women. Am J Clin Nutr 2003; 78
post-obese subjects. Obes Res 2000; 8 (3): 205-10
(1): 31-9
48. Jenkins AB, Markovic TP, Fleury A, et al. Carbohydrate intake
31. Tsai AC, Sandretto A, Chung YC. Dieting is more effective in and short-term regulation of leptin in humans. Diabetologia
reducing weight but exercise is more effective in reducing fat 1997; 40 (3): 348-51
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
260 Stiegler & Cunliffe
49. Demling RH, DeSanti L. Effect of a hypocaloric diet, increased carbohydrate vs high fat diets measured in a respiration cham-
protein intake and resistance training on lean mass gains and ber. Eur J Clin Nutr 1999; 53 (6): 495-502
fat mass loss in overweight police officers. Ann Nutr Metab
68. Westerterp-Plantenga MS, Lejeune M, Nijs I, et al. High protein
2000; 44 (1): 21-9
intake sustains weight maintenance after body weight loss in
50. Whitehead JM, McNeill G, Smith JS. The effect of protein
humans. Int J Obes 2004; 28 (1): 57-64
intake on 24-h energy expenditure during energy restriction.
69. Poppitt SD, McCormack D, Buffenstein R. Short-term effects of
Int J Obes 1996; 20 (8): 727-32
macronutrient preloads on appetite and energy intake in lean
51. Sloth B, Krog-Mikkelsen I, Flint A, et al. No difference in body
women. Physiol Behav 1998; 64 (3): 279-85
weight decrease between a low-glycemic-index and a high-
70. Latner JD, Schwartz M. The effects of a high-carbohydrate,
glycemic-index diet but reduced LDL cholesterol after 10-wk
high-protein or balanced lunch upon later food intake and
ad libitum intake of the low-glycemic-index diet. Am J Clin
hunger ratings. Appetite 1999; 33 (1): 119-28
Nutr 2004; 80 (2): 337-47
71. Stubbs RJ, van Wyk MCW, Johnstone AM, et al. Breakfasts
52. Mueller-Cunningham WM, Quintana R, Kasim-Karakas SE. An
high in protein, fat or carbohydrate: effect on within-day
ad libitum, very low-fat diet results in weight loss and changes
appetite and energy balance. Eur J Clin Nutr 1996; 50 (7):
in nutrient intakes in postmenopausal women. J Am Diet
Assoc 2003; 103 (12): 1600-6
72. Raben A, Agerholm-Larsen L, Flint A, et al. Meals with similar
53. Schlundt DG, Hill JO, Popecordle J, et al. Randomized evalua-
energy densities but rich in protein, fat, carbohydrate, or alco-
tion of a low-fat ab libitum carbohydrate-diet for weight-
hol have different effects on energy expenditure and substrate
reduction. Int J Obes 1993; 17 (11): 623-9
metabolism but not on appetite and energy intake. Am J Clin
54. Turley ML, Skeaff CM, Mann JI, et al. The effect of a low-fat,
Nutr 2003; 77 (1): 91-100
high-carbohydrate diet on serum high density lipoprotein cho-
73. Vozzo R, Wittert G, Cocchiaro C, et al. Similar effects of foods
lesterol and triglyceride. Eur J Clin Nutr 1998; 52 (10): 728-32
high in protein, carbohydrate and fat on subsequent spontane-
55. Brand-Miller JC, Holt SHA, Pawlak DB, et al. Glycemic index
ous food intake in healthy individuals. Appetite 2003; 40 (2):
and obesity. Am J Clin Nutr 2002; 76 (1): 281S-5S
56. Brehm BJ, Spang SE, Lattin BL, et al. The role of energy
74. Foster GD, Wyatt HR, Hill JO, et al. A randomized trial of a
expenditure in the differential weight loss in obese women on
low-carbohydrate diet for obesity. N Engl J Med 2003; 348
low-fat and low-carbohydrate diets. J Clin Endocrinol Metab
(21): 2082-90
2005; 90 (3): 1475-82
57. Skov AR, Toubro S, Ronn B, et al. Randomized trial on protein
75. Samaha FF, Iqbal N, Seshadri P, et al. A low-carbohydrate as
vs carbohydrate in ad libitum fat reduced diet for the treatment
compared with a low-fat diet in severe obesity. N Engl J Med
of obesity. Int J Obes 1999; 23 (5): 528-36
2003; 348 (21): 2074-81
58. Baba NH, Sawaya S, Torbay N, et al. High protein vs high
76. Eisenstein J, Roberts SB, Dallal G, et al. High-protein weight-
carbohydrate hypoenergetic diet for the treatment of obese
loss diets: are they safe and do they work? A review of the
hyperinsulinemic subjects. Int J Obes 1999; 23 (11): 1202-6
experimental and epidemiologic data. Nutr Rev 2002; 60 (7):
59. Luscombe-Marsh ND, Noakes M, Wittert GA, et al. Carbohy-
drate-restricted diets high in either monounsaturated fat or
77. Kerstetter JE, O’Brien KO, Insogna KL. Dietary protein, calci-
protein are equally effective at promoting fat loss and improv-
um metabolism, and skeletal homeostasis revisited. Am J Clin
ing blood lipids. Am J Clin Nutr 2005; 81 (4): 762-72
Nutr 2003; 78 (3): 584S-92S
60. Luscombe ND, Clifton PM, Noakes M, et al. Effect of a high-
78. Massey LK. Dietary animal and plant protein and human bone
protein, energy-restricted diet on weight loss and energy ex-
health: a whole foods approach. J Nutr 2003; 133 (3): 862S-5S
penditure after weight stabilization in hyperinsulinemic sub-
79. Ryan AS. Insulin resistance with aging: effects of diet and
jects. Int J Obes 2003; 27 (5): 582-90
exercise. Sports Med 2000; 30 (5): 327-46
61. McCrory MA, Suen VMM, Roberts SB. Biobehavioral influ-
80. Maehlum S, Grandmontagne M, Newsholme EA, et al. Magni-
ences on energy intake and adult weight gain. J Nutr 2002; 132
tude and duration of excess postexercise oxygen-consumption
(12): 3830S-4S
in healthy-young subjects. Metabolism 1986; 35 (5): 425-9
62. de Jonge L, Bray GA. The thermic effect of food and obesity: a
81. Borsheim E, Bahr R. Effect of exercise intensity, duration and
critical review. Obes Res 1997; 5 (6): 622-31
mode on post-exercise oxygen consumption. Sports Med 2003;
63. Nair KS, Halliday D, Garrow JS. Thermic response to
33 (14): 1037-60
isoenergetic protein, carbohydrate or fat meals in lean and
82. Frey GC, Byrnes WC, Mazzeo RS. Factors influencing excess
obese subjects. Clin Sci 1983; 65 (3): 307-12
postexercise oxygen-consumption in trained and untrained wo-
64. Jequier E. Pathways to obesity. Int J Obes 2002; 26: S12-7
men. Metabolism 1993; 42 (7): 822-8
65. Layman DK, Baum JI. Dietary protein impact on glycemic
83. Short KR, Sedlock DA. Excess postexercise oxygen consump-
control during weight loss. J Nutr 2004; 134 (4): 968S-73S
tion and recovery rate in trained and untrained subjects. J Appl
66. McCrory MA, Fuss PJ, Saltzman E, et al. Dietary determinants
Physiol 1997; 83 (1): 153-9
of energy intake and weight regulation in healthy adults. J Nutr
2000; 130 (2): 276S-9S
84. Sjodin AM, Forslund AH, Westerterp KR, et al. The influence
67. Westerterp-Plantenga MS, Rolland V, Wilson SAJ, et al. Satiety of physical activity on BMR. Med Sci Sports Exerc 1996; 28
related to 24h diet-induced thermogenesis during high protein (1): 85-91
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
The Role of Diet and Exercise During Weight Loss 261
85. Melby C, Scholl C, Edwards G, et al. Effect of acute resistance 101. Sykes K, Choo LL, Cotterrell M. Accumulating aerobic exercise
exercise on postexercise energy-expenditure and resting meta- for effective weight control. J R Soc Health 2004; 124 (1):
bolic-rate. J Appl Physiol 1993; 75 (4): 1847-53 24-8
86. Tonkonogi M, Krook A, Walsh B, et al. Endurance training
102. Schmitz KH, Jensen MD, Kugler KC, et al. Strength training for
increases stimulation of uncoupling of skeletal muscle mito-
obesity prevention in midlife women. Int J Obes 2003; 27 (3):
chondria in humans by non-esterified fatty acids: an uncou-
pling-protein-mediated effect? Biochem J 2000; 351: 805-10
103. Cullinen K, Caldwell M. Weight training increases fat free mass
87. Schrauwen P, Hesselink M. Uncoupling protein 3 and physical
and strength in untrained young women. J Am Diet Assoc
activity: the role of uncoupling protein 3 in energy metabolism
1998; 98 (4): 414-8
revisited. Proc Nutr Soc 2003; 62 (3): 635-43
104. Byrne HK, Wilmore JH. The effects of a 20-week exercise
88. Short KR, Vittone JL, Bigelow ML, et al. Age and aerobic
training program on resting metabolic rate in previously seden-
exercise training effects on whole body and muscle protein
tary, moderately obese women. Int J Sport Nutr Exerc Metab
metabolism. Am J Physiol Endocrinol Metab 2004; 286 (1):
2001; 11 (1): 15-31
105. Walberg JL. Aerobic exercise and resistance weight-training
89. Poehlman ET, Gardner AW, Goran MI. Influence of endurance
during weight-reduction: implications for obese persons and
training on energy intake, norepinephrine kinetics, and meta-
athletes. Sports Med 1989; 7 (6): 343-56
bolic rate in older individuals. Metabolism 1992; 41 (9): 941-8
106. Speakman JR, Selman C. Physical activity and resting metabol-
90. Horton TJ, Drougas HJ, Sharp TA, et al. Energy-balance in
ic rate. Proc Nutr Soc 2003; 62: 621-34
endurance-trained female cyclists and untrained controls. J
107. Warwick PM, Garrow JS. The effect of addition of exercise to a
Appl Physiol 1994; 76 (5): 1937-45
regime of dietary restriction on weight-loss, nitrogen-balance,
91. Westerterp KR, Meijer GAL, Schoffelen P, et al. Body-mass,
resting metabolic-rate and spontaneous physical-activity in 3
body-composition and sleeping metabolic-rate before, during
obese women in a metabolic ward. Int J Obes 1981; 5 (1):
and after endurance training. Eur J Appl Physiol Occup Physi-
ol 1994; 69 (3): 203-8
108. Woo R, Garrow JS, Pisunyer FX. Effect of exercise on sponta-
92. Venables MC, Achten J, Jeukendrup AE. Determinants of fat
neous calorie intake in obesity. Am J Clin Nutr 1982; 36 (3):
oxidation during exercise in healthy men and women: a cross-
sectional study. J Appl Physiol 2005 Jan; 98 (1): 160-7. Epub
2004 Aug 27
109. Klausen B, Toubro S, Ranneries C, et al. Increased intensity of a
single exercise bout stimulates subsequent fat intake. Int J
93. Abdel-Hamid TK. Modeling the dynamics of human energy
Obes 1999; 23 (12): 1282-7
regulation and its implications for obesity treatment. System
Dynamics Rev 2002; 18 (4): 431-71
110. Lluch A, King NA, Blundell JE. No energy compensation at the
94. van Aggel-Leijssen DP, Saris WH, Wagenmakers AJ, et al. The
meal following exercise indietary restrained and unrestrained
effect of low-intensity exercise training on fat metabolism of
women. Br J Nutr 2000; 84 (2): 219-25
obese women. Obes Res 2001; 9 (2): 86-96
111. Kempen KPG, Saris WHM, Westerterp KR. Energy-balance
95. Wilmore JH, Despres JP, Stanforth PR, et al. Alterations in body
during an 8-wk energy-restricted diet with and without exer-
weight and composition consequent to 20 wk of endurance
cise in obese women. Am J Clin Nutr 1995; 62 (4): 722-9
training: the HERITAGE Family Study. Am J Clin Nutr 1999;
112. Stubbs RJ, Sepp A, Hughes DA, et al. The effect of graded
70 (3): 346-52
intake and balance levels of exercise on energy in free-living
96. Donnelly JE, Hill JO, Jacobsen DJ, et al. Effects of a 16-month
women. Int J Obes 2002; 26 (6): 866-9
randomized controlled exercise trial on body weight and com-
113. Stubbs RJ, Hughes DA, Johnstone AM, et al. Rate and extent of
position in young, overweight men and women: the midwest
compensatory changes in energy intake and expenditure in
excercise trial. Arch Intern Med 2003; 163 (11): 1343-50
response to altered exercise and diet composition in humans.
97. Kirk EP, Jacobsen DJ, Gibson C, et al. Time course for changes
Am J Physiol Regul Integr Comp Physiol 2004; 286 (2):
in aerobic capacity and body composition in overweight men
and women in response to long-term exercise: the Midwest
114. Provencher V, Drapeau V, Tremblay A, et al. Eating behaviors
Exercise Trial (MET). Int J Obes 2003; 27 (8): 912-9
and indexes of body composition in men and women from the
98. Wilmore JH, Stanforth PR, Hudspeth LA, et al. Alterations in
Quebec family study. Obes Res 2003; 11 (6): 783-92
resting metabolic rate as a consequence of 20 wk of endurance
115. Visona C, George VA. Impact of dieting status and dietary
training: the HERITAGE Family Study. Am J Clin Nutr 1998;
restraint on postexercise energy intake in overweight women.
68 (1): 66-71
Obes Res 2002; 10 (12): 1251-8
99. Grediagin MA, Cody M, Rupp J, et al. Exercise intensity does
116. Frey-Hewitt B, Vranizan KM, Dreon DM, et al. The effect of
net effect body-composition change in untrained, moderately
weight loss by dieting or exercise on resting metabolic rate in
overfat women. J Am Diet Assoc 1995; 95 (6): 661-5
overweight men. Int J Obes 1990; 14 (4): 327-34
100. Donnelly JE, Jacobsen DJ, Heelan KS, et al. The effects of 18
months of intermittent vs continuous exercise on aerobic ca- 117. Hays NP, Starling RD, Liu XL, et al. Effects of an ad libitum
pacity, body weight and composition, and metabolic fitness in low-fat, high-carbohydrate diet on body weight, body compo-
previously sedentary, moderately obese females. Int J Obes sition, and fat distribution in older men and women: a random-
2000; 24 (5): 566-72 ized controlled trial. Arch Intern Med 2004; 164 (2): 210-7
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
262 Stiegler & Cunliffe
118. Okura T, Nakata Y, Tanaka K. Effects of exercise intensity on subjects during a short-term body mass reduction program. J
physical fitness and risk factors for coronary heart disease. Endocrinol Invest 2003; 26 (3): 197-205
Obes Res 2003; 11 (9): 1131-9
133. Forbes GB. Diet and exercise in obese subjects: self-report
versus controlled measurements. Nutr Rev 1993; 51 (10):
119. Racette SB, Schoeller DA, Kushner RF, et al. Effects of aerobic
exercise and dietary carbohydrate on energy-expenditure and
body-composition during weight-reduction in obese rate. Am J
134. Andersen RE, Franckowiak SC, Bartlett SJ, et al. Physiologic
Clin Nutr 1995; 61 (3): 486-94
changes after diet combined with structured aerobic exercise or
lifestyle activity. Metabolism 2002; 51 (12): 1528-33
120. Gornall J, Villani RG. Short-term changes in body composition
and metabolism with severe dieting and resistance exercise. Int
135. Forbes GB. Body fat content influences the body composition
J Sport Nutr 1996; 6 (3): 285-94
response to nutrition and exercise. Ann N Y Acad Sci 2000;
904: 359-65
121. Doi T, Matsuo T, Sugawara M, et al. New approach for weight
reduction by a combination of diet, light resistance exercise
136. Lennon D, Nagle F, Stratman F, et al. Diet and exercise training
and the timing of ingesting a protein supplement. Asia Pac J
effects on resting metabolic rate. Int J Obes 1985; 9 (1): 39-47
Clin Nutr 2001; 10 (3): 226-32
137. Poehlman ET. Exercise and its influence on resting energy-
122. Rice B, Janssen I, Hudson R, et al. Effects of aerobic or
metabolism in man: a review. Med Sci Sports Exerc 1989; 21
resistance exercise and/or diet on glucose tolerance and plasma
(5): 515-25
insulin levels in obese men. Diabetes Care 1999; 22 (5):
138. Poehlman ET, Horton ES. The impact of food-intake and exer-
cise on energy-expenditure. Nutr Rev 1989; 47 (5): 129-37
123. Janssen I, Fortier A, Hudson R, et al. Effects of an energy-
139. Schuenke MD, Mikat RP, McBride JM. Effect of an acute
restrictive diet with or without exercise on abdominal fat,
period of resistance exercise on excess post-exercise oxygen
intermuscular fat, and metabolic risk factors in obese women.
consumption: implications for body mass management. Eur J
Diabetes Care 2002; 25 (3): 431-8
Appl Physiol 2002; 86 (5): 411-7
124. Geliebter A, Maher MM, Gerace L, et al. Effects of strength or
140. Osterberg KL, Melby CL. Effect of acute resistance exercise on
aerobic training on body composition, resting metabolic rate,
postexercise oxygen consumption and resting metabolic rate in
and peak oxygen consumption in obese dieting subjects. Am J
young women. Int J Sport Nutr 2000; 10 (1): 71-81
Clin Nutr 1997; 66 (3): 557-63
141. De Feo P, Di Loreto C, Lucidi P, et al. Metabolic response to
125. Bryner RW, Ullrich IH, Sauers J, et al. Effects of resistance vs.
exercise. J Endocrinol Invest 2003; 26 (9): 851-4
aerobic training combined with an 800 calorie liquid diet on
142. Reynolds TH, Brown MD, Supiano MA, et al. Aerobic exercise
lean body mass and resting metabolic rate. J Am Coll Nutr
training improves insulin sensitivity independent of plasma
1999; 18 (2): 115-21
tumor necrosis factor-alpha levels in older female hyperten-
126. Marks BL, Ward A, Morris DH, et al. Fat-free mass is main-
sives. Metabolism 2002; 51 (11): 1402-6
tained in women following a moderate diet and exercise pro-
143. Goodpaster BH, Katsiaras A, Kelley DE. Enhanced fat oxida-
gram. Med Sci Sports Exerc 1995; 27 (9): 1243-51
tion through physical activity is associated with improvements
127. Wadden TA, Vogt RA, Kuehnel RH, et al. Exercise in the
in insulin sensitivity in obesity. Diabetes 2003; 52 (9): 2191-7
treatment of obesity: effects of four interventions on body
144. Schrauwen P, Lichtenbelt WDV, Saris WHM, et al. Fat balance
composition, resting energy expenditure, appetite, and mood. J
in obese subjects: role of glycogen stores. Am J Physiol 1998;
Consult Clin Psychol 1997; 65 (2): 269-77
37 (6): E1027-33
128. Kraemer WJ, Volek JS, Clark KL, et al. Physiological adapta-
145. Binzen CA, Swan PD, Manore MM. Postexercise oxygen con-
tions to a weight-loss dietary regimen and exercise programs in
sumption and substrate use after resistance exercise in women.
women. J Appl Physiol 1997; 83 (1): 270-9
Med Sci Sports Exerc 2001; 33 (6): 932-8
129. Svendsen OL, Hassager C, Christiansen C. Effect of an energy-
146. Mayo MJ, Grantham JR, Balasekaran G. Exercise-induced
restrictive diet, with or without exercise, on lean tissue mass,
weight loss preferentially reduces abdominal fat. Med Sci
resting metabolic-rate, cardiovascular risk-factors, and bone in
Sports Exerc 2003; 35 (2): 207-13
overweight postmenopausal women. Am J Med 1993; 95 (2):
147. Lindstrom J, Louheranta A, Mannelin M, et al. The Finnish
Diabetes Prevention Study (DPS). Diabetes Care 2003; 26
130. Evans WJ. Protein nutrition and resistance exercise. Can J Appl
(12): 3230-6
Physiol 2001; 26: S141-52
131. Doi T, Matsuo T, Sugawara M, et al. New approach for weight
reduction by a combination of diet, light resistance exercise
Correspondence and offprints: Petra Stiegler, Department of
and the timing of ingesting a protein supplement. Asia Pacific J
Human and Health Sciences, School of Biosciences, Univer-
Clin Nutr 2001; 10 (3): 226-32
sity of Westminster, 115 New Cavendish Street, London,
132. Lafortuna CL, Resnik M, Galvani C, et al. Effects of non-
W1W 6UW, UK.
specific vs individualized exercise training protocols on aero-
bic anaerobic and strength performance in severely obese E-mail:
2006 Adis Data Information BV. All rights reserved. Sports Med 2006; 36 (3)
... In modern medicine, one of the best ways to lose weight is a balanced lowcalorie diet, in which it is recommended to reduce the energy intake of obese people by 500 to 1000 calories [9]. Combining physical activity with diet to maintain muscle mass is one of the most basic methods of weight loss [10,11]. Physical activity helps control weight by increasing basal metabolism, fat oxidation and maintaining muscle mass [11,17]. ...
... Combining physical activity with diet to maintain muscle mass is one of the most basic methods of weight loss [10,11]. Physical activity helps control weight by increasing basal metabolism, fat oxidation and maintaining muscle mass [11,17]. Given that no research has examined the effect of traditional Iranian medicine on obese people (diet based on temperament), the researcher intends to study the effect of traditional Iranian medicine and modern medicine on weight loss and blood lipids. ...
... Reducing WHR, improving lipid factors and blood sugar can be related to weight loss, to some extent the effects of physical activity and putting the right ratio of macronutrients in their diet. When weight loss is normal, most of the weight loss will be due to fat mass [9,11,17]. In the group of modern medicine, reducing 700 calories from energy intake is appropriate and will not have much effect on reducing muscle mass. ...
... Un large consensus dans la littérature scientifique met en évidence les bénéfices d'une AP régulière pour la santé, notamment la réduction du risque de mortalité précoce de 29% à 41% (Nocon et al., 2008). Cette réduction du risque de mortalité s'explique par l'effet bénéfique de d'une AP régulière sur différents paramètres de santé : le risque cardiovasculaire (e.g., diminution du risque de pathologies coronariennes de 15% à 21% chez les hommes et de 22% à 29% chez les femmes (INSERM, 2008), le surpoids et l'obésité (e.g., associée à une maîtrise de l'apport calorique, l'AP constitue le traitement le plus efficace de l'obésité ; (Stiegler & Cunliffe, 2006), le diabète de type 2 (e.g., l'AP régulière permet de réduire de 30% le risque de diabète de type 2 ; (Jeon, Lokken, Hu, & van Dam, 2007), l'hypertension artérielle (e.g., les programmes d'entrainement aérobie diminuent significativement la pression artérielle ; (Whelton, Chin, Xin, & He, 2002), et le cancer (l'AP diminue de 25 à 40% le risque de cancer ; (Whelton et al., 2002). ...
Full-text available
Cette note de synthèse réalisée en vue de l’obtention de l’Habilitation à Diriger des Recherches vise à retracer les éléments saillants de mes travaux de recherche portant sur la promotion de la motivation à l’École et en contexte sportif, et sur la promotion de la motivation pour l’activité physique (AP) à des fins de santé. Elle est structurée en trois parties : La première porte sur la promotion de la motivation pour l’AP à des fins de santé. Les travaux qui s’inscrivent sur cet axe de recherche se sont intéressés à trois mécanismes de promotion de l’AP : des mécanismes cognitifs visant le développement des intentions d’AP, des mécanismes comportementaux visant le développement des capacités d’autorégulation facilitant l’implémentation des intentions, et des mécanismes affectifs visant le développement d’expériences d’AP positives. La deuxième partie concerne la promotion de la motivation en EPS et en sport. Les travaux menés dans cette perspective, ont consisté à élaborer, tester, et répliquer plusieurs programmes de formation des enseignants et des entraineurs à dessein d’améliorer leur style motivationnel, ainsi que l’engagement et la motivation autonome de leurs élèves/sportifs. Enfin, la troisième partie s’intéresse à la promotion de la motivation et du bien-être à l’école. Les travaux relatifs à cet axe se sont notamment intéressés au développement des compétences psychosociales des élèves en tant que vecteur de promotion de la motivation et du bien-être. Le projet ProMoBE consistant à combiner des leviers de la promotion de la motivation (i.e., formation au soutien des besoins psychologiques visant l’amélioration du style motivationnel) et des leviers de la promotion du bien-être (i.e., IPP-multi-composantes visant le développement des CPS) représente le coeur de cet axe de recherche.
... Secondly, unlike the placebo group, the collagen group was able to maintain their resting energy expenditure (REE) due to the preservation and increase of FFM, which is considered to have played an important role (52). REE, which is strongly correlated with muscle mass, accounts for the majority (60-70%) of daily energy expenditure (53,54), and thus, it becomes challenging to maintain a continuous negative energy balance when REE is reduced (52). Therefore, it is important to maintain a REE by preserving muscle mass (55). ...
Full-text available
BACKGROUND: Insufficient protein intake can accelerate the loss of muscle mass as one ages. A decrease in muscle mass leads to an increase in fat mass, creating a vicious cycle that can result in sarcopenic obesity. Previous studies that have used collagen as a supplementation, which accounts for about 30% of the body's protein, have combined it with resistance exercise. OBJECTIVE: This study investigated the effects of collagen supplementation on body composition in individuals over the age of 50, while maintaining their daily activity levels constant. DESIGN: Double-blind randomized controlled trial PARTICIPANTS: Participants were assigned to either the collagen group (n=42) or the placebo group(n=42). MEASUREMENTS: Collagen supplementation (14g of collagen) and placebo product (xanthan gum) were offered to collagen group and placebo group respectively, once a day. Body composition was measured by bioelectrical impedance analysis and dual-energy X-ray absorptiometry. Participants were instructed to maintain their dietary intake and physical activity levels, which were evaluated through a 3-day food record analysis and an international physical activity questionnaire (IPAQ) analysis, respectively. RESULTS: 74 participants in the collagen group (n=37) and placebo group (n=37) completed the follow-up, and there was no significant difference between the two groups in terms of physical activity levels. The collagen group showed a significant reduction in total body fat mass compared to the placebo group, as evidenced by both BIA (P=0.021) and DEXA (P=0.041) measurements. However, there was no significant difference between the two groups in terms of muscle mass. Conclusion: From this study, the consumption of collagen supplementation is effective in reducing fat mass, which is significant in preventing sarcopenic obesity after middle age.
... While the vast majority of options for treatment offer short-term improvements, across any method of intervention, there is poor long-term success and even less success for preventing issues of overfatness (Clark and Goon, 2015;Connolly et al., 1999;Hafekost et al., 2013;Stiegler and Cunliffe, 2006). In addition, existing models for the prevention and treatment of overfatness over rely on group trends that fail to see health behaviours as individual phenomenon (Lappalainen et al., 2014). ...
The use of diet and exercise has become the cornerstone to treatment of overfatness issues. Yet, the implementation of such factors into lifestyle changes has not been able to meet intrinsic expectations or desires and has led to continuous repetition of short-term success within a coercive environment that is followed by rebound leading to secondary short-term success, that is yo-yo’ing. Even though this has become common, there has been little insight into how we might be able to improve suggestions for diet and exercise to better encourage long-term success as opposed to the short-term gains that are regularly met. In this commentary, we offer a narrative review describing how the use of behavioural analytic methodologies and techniques might allow for the development of self-selective lifestyle modifications (e.g. changes to diet, use of exercise) and choices in behaviour that better serve individuals attempting to reverse the health issues associated with overfatness, without the sense of their being coerced into their choices.
... Appropriate nutrient intake is also required to promote increases in the muscle mass or FFM through physical activity or exercise. According to a review article on weight loss through exercise and diet (Stiegler and Cunliffe, 2006), researchers have observed that weight loss through exercise was also accompanied by a reduction in FFM depending on the nutritional intake status. For instance, in a study examined the effects of increased physical activity and decreased energy intake on weight loss in a population including normal-weight individuals reported that lower protein intake was associated with a higher percentage reduction in FFM (Pasiakos et al., 2013). ...
This study investigated the association between nutritional intake and indices of muscle mass or strength in 104 female Japanese university students who participated in sports activities during their junior and senior high school periods and had a high current physical activity level (PAL). Body composition was measured by the bioelectrical impedance method, and appendicular muscle mass (AMM) and skeletal muscle mass index (SMI) were evaluated as muscle mass. PAL was estimated using a factorial method and nutritional intake status was investigated using a food frequency questionnaire based on food groups (FFQg). Grip strength was measured as an index of muscle strength. According to the criteria for diagnosis of sarcopenia, four of the participants had low muscle mass and one also had low grip strength. Although there were no significant differences in body size or grip strength between participants with a high versus low SMI, participants with a low SMI had a significantly higher percentage of body fat (27.7 ± 4.7% vs. 23.3 ± 4.1%), and significantly lower AMM (16.0 ± 1.4 kg vs. 20.6 ± 1.5 kg), total energy intake (1770.4 ± 386.5 kcal/d vs. 2017.1 ± 389.9 kcal/d), and protein intake (57.3 ± 15.0 g/d vs. 67.0 ± 14.2 g/d), as well as a tendency to have a significantly lower carbohydrate intake (239.6 ± 49.3 g/d vs. 268.1 ± 54.4 g/d), than those with a high SMI. These results indicate that even some female university students with a high PAL have a lower muscle mass and might have a low dietary intake, mainly protein and carbohydrate. The results of multiple regression analysis of AMM, SMI, or grip strength with PAL and nutrient intake revealed that PAL and total energy intake or protein intake were significantly and positively associated with muscle mass and strength. These results suggest that a high PAL as well as total energy intake and protein intake among the macronutrients contribute to high muscle mass and muscle strength in young women.
... In corso di DK si possono avere alcuni effetti collaterali lievi e transitori: alitosi, mal di testa, scarsa tolleranza al freddo, effluvium, irritabilità, vertigini posturali e, in alcuni casi, stitichezza [9]. Inoltre, se la DK è sicuramente efficace nel ridurre la massa grassa non bisogna dimenticare che la restrizione energetica può portare a una riduzione della massa magra [10]. ...
Full-text available
Sommario La dieta chetogenica (DK) ha guadagnato un’immensa popolarità nell’ultimo decennio, principalmente a causa del suo effetto a breve termine sulla perdita di peso e per il beneficio teorizzato sull’adattamento muscolare in corso di esercizio fisico. Durante l’allenamento, aderire a un regime DK determina un rapido cambiamento di “energia” e un conseguente adattamento che conduce a un maggiore ossidazione degli acidi grassi in presenza di ridotte riserve di glicogeno muscolare. Questa rassegna vuole rilevare i benefici e i rischi associati all’uso della DK in corso di esercizio fisico in diverse popolazioni (atleti, soggetti allenati, pazienti affetti da obesità) focalizzando maggiormente l’attenzione sul mantenimento della massa muscolare.
Time-restricted feeding (TRF) has increased in popularity among various groups, including fitness enthusiasts. The ideal timing of TRF in relation to daily exercise is unknown. Most fitness enthusiasts consume meals immediately or soon after exercise to improve body composition (e.g., lean mass). We compared two different TRF approaches, as well as an ad libitum control diet, with regards to body mass and body composition in C57BL/6 mice . Young, healthy, male mice exercised five days per week and were assigned to consume food ad libitum (control), or to follow a 6-hour TRF that began immediately after exercise (TRF-I) or 5 hours after exercise (TRF-D); n = 12 mice per group. Body mass, lean mass, and fat mass were assessed weekly. Due to animal deaths, only 10 animals were included in the analysis for each TRF group, with 8 animals included for the control group. When computing the 8-week average, body mass varied between groups (p < 0.0001), with the TRF-I (25.4 ± 1.7 g) weighing less than the TRF-D (26.3 ± 2.3 g) and control (26.9 ± 2.3 g). Lean mass also differed (p < 0.0001), with control (22.8 ± 1.9 g) higher than TRF-I (21.4 ± 1.7 g) and TRF-D (21.7 ± 1.8 g). Additionally, fat mass differed between groups (p < 0.0001), with the TRF-D (2.7 ± 0.9 g) higher than the TRF-I (2.2 ± 0.9 g) and control (2.0 ± 1.2 g). Finally, percent body fat differed (p < 0.0001), with TRF-D (10.5 ± 3.3%) higher than TRF-I (8.6 ± 3.7%) and control (7.5 ± 4.3%). At the end of the 8-week intervention, TRF-I was lower in fat mass and percent body fat than TRF-D (p < 0.05), while body mass and lean mass were higher for control as compared to both TRF groups (p < 0.05). These results indicate that when combined with regular exercise, ad libitum feeding may be more beneficial (greater overall and lean mass gain) than TRF, regardless of feeding timing.
Full-text available
Background: The purpose of this study was to examine the associations of self-reported happiness with body mass index and obesity risks among young adults aged in Taiwan. Methods: A cross-sectional study was conducted with secondary data sets from the Taiwan National Physical Activity Survey, a nationally representative survey of Taiwan's population. A total of 10,638 young adults aged 18-44 years were ultimately enrolled in this study from August to October 2020. Demographic characteristics, self-reported health status, self- evaluations (comprising height, body weight, and happiness), and zip code of residence were among the data obtained through the national telephone survey. Results: The results showed that after adjusting for potential confounders in the unhappy group, the obesity was significantly associated with happiness. (odds ratio [OR] = 0.637, 95% confidence interval [CI]: 0494-0.820, p < 0.001). Conclusions: The present study revealed that body component and obesity risk are the factors affecting happiness among young adults in Taiwan. Moreover, obesity showed the negative correlation with happiness after adjusting for confounding factors.
Although surgical techniques have greatly improved over the last decades, operative complication risks associated with bariatric surgery still being a concern in this type of surgery. This surgical risk can be reduced by improving the physical fitness and the obesity-related comorbidities of bariatric patients. Due to the benefits of exercise on these variables, adding an exercise program to prehabilitation is postulated to become a highly effective strategy to treat these clinical variables. This chapter deals with the reasons why operative complications can occur, emphasizes the parameters on which exercise can affect, and provides general guidelines for the development of an exercise program targeted to patients awaiting bariatric surgery.KeywordsBariatric surgeryExercisePhysical activityPrehabilitationPostoperative complications
Full-text available
Bu araştırmada üniversite öğrencilerinin sağlıklı beslenmeye yönelik tutumları cinsiyet, bazal metabolik hız düzeyleri, günlük su tüketim miktarları ve vitamin desteği alma durumları açısından incelenmiştir. Araştırmaya 2022-2023 eğitim ve öğretim yılı içerisinde Iğdır Üniversitesi bünyesinde yer alan fakülte ve yüksekokullarda öğrenim gören 201 erkek ve 99 kadın olmak üzere toplam 300 öğrenci katılmıştır. Veriler “Kişisel Bilgi Formu”, ve “Sağlıklı Beslenmeye İlişkin Tutum Ölçeği (SBİTÖ) kullanılarak toplanmıştır. Yapılan analiz sonucunda elde edilen veriler normal dağılım göstermediği için non-parametrik testlerden yararlanılmıştır. Öğrencilerin bazal metabolik hızlarının belirlenmesinde “Yoncalık BMH Denklemi” kullanılmıştır. Sonuç olarak erkek öğrenciler ile kadın öğrenciler arasında “Beslenme Hakkında Bilgi” ve “Olumlu Beslenme” alt boyutlarında erkekler lehine istatistiki fark olduğu tespit edilmiştir (p
Full-text available
Although weight loss can be achieved by any means of energy restriction, current dietary guidelines have not prevented weight regain or population-level increases in obesity and overweight. Many high-carbohydrate, low-fat diets may be counterproductive to weight control because they markedly increase postprandial hyperglycemia and hyperinsulinemia. Many high-carbohydrate foods common to Western diets produce a high glycemic response [high-glycemic-index (GI) foods], promoting postprandial carbohydrate oxidation at the expense of fat oxidation, thus altering fuel partitioning in a way that may be conducive to body fat gain. In contrast, diets based on low-fat foods that produce a low glycemic response (low-GI foods) may enhance weight control because they promote satiety, minimize postprandial insulin secretion, and maintain insulin sensitivity. This hypothesis is supported by several intervention studies in humans in which energy-restricted diets based on low-GI foods produced greater weight loss than did equivalent diets based on high-GI foods. Long-term studies in animal models have also shown that diets based on high-GI starches promote weight gain, visceral adiposity, and higher concentrations of lipogenic enzymes than do isoenergetic, macronutrientcontrolled, low-GI-starch diets. In a study of healthy pregnant women, a high-GI diet was associated with greater weight at term than was a nutrient-balanced, low-GI diet. In a study of diet and complications of type 1 diabetes, the GI of the overall diet was an independent predictor of waist circumference in men. These findings provide the scientific rationale to justify randomized, controlled, multicenter intervention studies comparing the effects of conventional and low-GI diets on weight control.
Full-text available
DE JONGE, LILIAN, GEORGE BRAY. The thermic effect of food and obesity: A critical review. This review has examined the factors that influence the thermic effect of food (TEF) by evaluating 49 studies that have compared subjects who are obese with those who are lean. Meal size, meal composition, the nature of the previous diet, insulin resistance, physical activity, and ageing influence TEF. In the studies of individuals who are obese or lean, of those who used intravenous glucose infusions, all but one found an impaired thermic response. A total of 29 out of 49 studies of individuals of normal weight or with obesity were identified where there was no difference in age between the groups, and where the subjects who were “overweight” were clearly obese. Of these 29, 22 reported a statistically significant reduction in TEF, 3 studies were not designed to look primarily at the effect of obesity on TEF, and the other 4 may not have had sufficiently palatable meals. From this review, we conclude that the reduction of TEF in obesity is related to the degree of insulin resistance, which may be influenced by a low level of sympathetic activity.
Full-text available
OBJECTIVE: To investigate the long-term effects of changes in dietary carbohydrate/fat ratio and simple vs complex carbohydrates.DESIGN: Randomized controlled multicentre trial (CARMEN), in which subjects were allocated for 6 months either to a seasonal control group (no intervention) or to one of three experimental groups: a control diet group (dietary intervention typical of the average national intake); a low-fat high simple carbohydrate group; or a low-fat high complex carbohydrate group.SUBJECTS: Three hundred and ninety eight moderately obese adults.MEASUREMENTS: The change in body weight was the primary outcome; changes in body composition and blood lipids were secondary outcomes.RESULTS: Body weight loss in the low-fat high simple carbohydrate and low-fat high complex carbohydrate groups was 0.9 kg (P
Kraemer, William J., Jeff S. Volek, Kristine L. Clark, Scott E. Gordon, Thomas Incledon, Susan M. Puhl, N. Travis Triplett-McBride, Jeffrey M. McBride, Margot Putukian, and Wayne J. Sebastianelli.Physiological adaptations to a weight-loss dietary regimen and exercise programs in women. J. Appl. Physiol. 83(1): 270–279, 1997.—Thirty-one women (mean age 35.4 ± 8.5 yr) who were overweight were matched and randomly placed into either a control group (Con; n = 6), a diet-only group (D; n = 8), a diet+aerobic endurance exercise training group (DE; n = 9), or a diet+aerobic endurance exercise training+strength training group (DES; n = 8). After 12 wk, the three dietary groups demonstrated a significant ( P ≤ 0.05) reduction in body mass, %body fat, and fat mass. No differences were observed in the magnitude of loss among groups, in fat-free mass, or in resting metabolic rate. The DE and DES groups increased maximal oxygen consumption, and the DES group demonstrated increases in maximal strength. Weight loss resulted in a similar reduction in total serum cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol among dietary groups. These data indicate that weight loss during moderate caloric restriction is not altered by inclusion of aerobic or aerobic+resistance exercise, but diet in conjunction with training can induce remarkable adaptations in aerobic capacity and muscular strength despite significant reductions in body mass.
Context Diabetes mellitus and elevated postload plasma glucose levels have been associated with an increased risk of pancreatic cancer in previous studies. By virtue of their influence on insulin resistance, obesity and physical inactivity may increase risk of pancreatic cancer.Objective To examine obesity, height, and physical activity in relation to pancreatic cancer risk.Design and Setting Two US cohort studies conducted by mailed questionnaire, the Health Professionals Follow-up Study (initiated in 1986) and the Nurses' Health Study (initiated in 1976), with 10 to 20 years of follow-up.Participants A total of 46 648 men aged 40 to 75 years and 117 041 women aged 30 to 55 years who were free of prior cancer at baseline and had complete data on height and weight.Main Outcome Measures Relative risk of pancreatic cancer, analyzed by self-reported body mass index (BMI), height, and level of physical activity.Results During follow-up, we documented 350 incident pancreatic cancer cases. Individuals with a BMI of at least 30 kg/m2 had an elevated risk of pancreatic cancer compared with those with a BMI of less than 23 kg/m2 (multivariable relative risk [RR], 1.72; 95% confidence interval [CI], 1.19-2.48). Height was associated with an increased pancreatic cancer risk (multivariable RR, 1.81; 95% CI, 1.31-2.52 for the highest vs lowest categories). An inverse relation was observed for moderate activity (multivariable RR, 0.45; 95% CI, 0.29-0.70 for the highest vs lowest categories; P for trend <.001). Total physical activity was not associated with risk among individuals with a BMI of less than 25 kg/m2 but was inversely associated with risk among individuals with a BMI of at least 25 kg/m2 (pooled multivariable RR, 0.59; 95% CI, 0.37-0.94 for the top vs bottom tertiles of total physical activity; P for trend = .04).Conclusion In 2 prospective cohort studies, obesity significantly increased the risk of pancreatic cancer. Physical activity appears to decrease the risk of pancreatic cancer, especially among those who are overweight.
Insulin resistance, a reduction in the rate of glucose disposal elicited by a given insulin concentration, is present in individuals who are obese, and those with diabetes mellitus, and may develop with aging. Methods which are utilised to measure insulin sensitivity include the hyperinsulinaemic-euglycaemic and hyperglycaemic clamps and the intravenous glucose tolerance tests. Several hormones and regulatory factors affect insulin action and may contribute to the insulin resistance observed in obesity. In addition, abnormal free fatty acid metabolism plays an important role in insulin resistance and the abnormal carbohydrate metabolism seen in individuals who are obese or diabetic. Thus, the mechanisms underlying the development of insulin resistance are multifactorial, and also involve alterations of the insulin signalling pathway. Aging is associated with an increase in bodyweight and fat mass. Not only is abdominal fat associated with hyperinsulinaemia but visceral adiposity is correlated with insulin resistance as well. Modifications of the changes in body composition with aging by diet and exercise training could delay the onset of insulin resistance. Weight loss and aerobic and resistive exercise training result in losses of total body fat and abdominal fat. Several studies report that bodyweight loss increases insulin sensitivity and improves glucose tolerance. In addition, the insulin resistance observed in aged persons can be modified by physical training. Longitudinal studies indicate significant improvements in glucose metabolism with aerobic exercise training in middle-aged and older men and women. Moreover, the improvements in insulin sensitivity with resistive training are similar in magnitude to those achieved with aerobic exercise. The improvements in glucose metabolism after bodyweight loss and exercise training may in some cases be partially attributed to changes in body composition, including reductions in total and central body fat. Yet, additional changes in skeletal muscle, blood flow and other mechanisms likely interact to modify insulin resistance with exercise training. Lifestyle modifications including bodyweight loss and physical activity provide health benefits and functional gains and should be promoted to increase insulin sensitivity and prevent glucose intolerance and type 2 diabetes mellitus in older adults.
This study tests the hypothesis that hyperinsulinemic (HI) obese subjects respond differently from normoinsulinemics (NI) to changes in composition of hypoenergetic diets. Twenty-seven obese male subjects, 13 HI and 14 NI, were fed for 4 weeks either a high protein (HP) or a high carbohydrate (HC) hypoenergetic diet providing 80% of their resting energy expenditure (REE). On the HP diet weight loss was significantly higher in HI as compared to NI group. Alternatively, the HI group lost less weight than NI group on the HC diet. The HC diets resulted in a considerable and similar reduction in REE in both HI and NI groups as opposed to the HP diet, which maintained REE in both HI and NI. A higher decrease and normalization of fasting insulin levels was observed in the HI group on the HP as compared to HC diet. In conclusion, hyperinsulinemic, in contrast to normoinsulinemic obese subjects, seem to achieve better weight reduction, less decline in energy expenditure, and normalization of insulin levels on HP than isocaloric HC diet.
Objective. —To examine the associations of body mass index (BMI) and weight change with risk of stroke in women.