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Fat Loss Depends on Energy Deficit Only, Independently of the Method for Weight Loss

Authors:

Abstract

This study was designed to compare the effects of 2 different but isocaloric fat reduction programs with the same amount of energy deficit - diet alone or diet combined with aerobic training - on body composition, lipid profile and cardiorespiratory fitness in non- or moderately obese women. Twenty non- or moderately obese (BMI 24.32 +/- 3.11) females (27.3 +/- 6.6 years) were tested at the beginning and after an 8-week period of a mild hypocaloric diet for the following parameters: (1) body mass and body fat; (2) total cholesterol, HDL-C, LDL-C and triglycerides; (3) lactate (millimol/liter) during submaximal exertion (100 W); (4) heart rate during submaximal exertion (100 W), and (5) maximum exercise performance (watt). Subjects were randomly divided into either a diet alone (D, -2,095 +/- 659 kJ/day) or a diet (-1,420 +/- 1,084 kJ/day) plus exercise (DE, three 60-min sessions per week at 60% of VO(2)max or -5,866 kJ/week) group. Body mass and body fat decreased significantly in D (-1.95 +/- 1.13 kg or -1.47 +/- 0.87%; p < 0.05) and DE (-2.23 +/- 1.28 kg or -1.59 +/- 0.87%; p < 0.05), but there was no significant difference observed between the groups. Statistical analysis revealed no significant changes of total cholesterol, HDL-C, LDL-C, triglycerides and heart rate during submaximal exertion (100 W). Lactic acid accumulation during submaximal exertion (100 W) decreased significantly (-0.8 +/- 1.4 mmol/l, p < 0.05) in DE and increased significantly (+0.4 +/- 0.5 mmol/l, p < 0.05) in D. Maximum exercise performance improved significantly (+12.2 +/- 8.8 W, p < 0.05) in DE and did not change significantly in D. This study showed that independently of the method for weight loss, the negative energy balance alone is responsible for weight reduction.
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Original Paper
Nutrition&
Metabolism
KeyWords
Diet . Exercise .Weight loss ' Energy balance '
Body composition . Lipid profile
Abstract
Background; This study was designed to compare the ef-
fects of 2 different but isocaloric fat reduction programs
with the same amount of energy deficit - diet alone or diet
combined with aerobic training - on body composition, lip-
id profile and cardiorespiratory fitness in non- or moderate-
ly obese women. Methods: Twenty non- or moderately
obese (BMl 24.32 + 3.11)females (21.2 + 6.6 years) were test-
ed at the beginning and after an S-week period of a mild
hypocaloric diet for the following parameters: (1) body mass
and body fau (2) total cholesterol, HDL-C, LDL-C and triglyc-
erides; (3) lactate (millimol/liter) during submaximal ex-
ertion (100 W); (4) heart rate during submaximal exertion
(100 W), and (5) maximum exercise performance (watt). Sub-
jects were randomly divided into either a diet alone (D,
-2,095 + 659 kJ/day) or a diet (-1,420 + 1,084 d/day)
plus exercise (DE, three 60-min sessions per week at 600/o of
VO2max or -5,866 kJlweek) group. Results: Body mass and
bodyfat decreased significantly in D (-1.95 + 1.13 kg or -1.47
+ 0.87o/o) p < 0.05) and DE (-2.21 + 1.28 kg or -1.59 + 0.87o/o;
Received: November 7, 2006
Accepted: April 20, 2007
Published online: November 20, 2007
p < 0.05), but there was no significant difference observed
between the groups. Statistical analysis revealed no signifi-
cant changes of total cholesterol, HDL-C, LDL-C, triglycerides
and heart rate during submaximal exertion (100 W). Lactic
acid accumulation during submaximal exertion (100 W) de-
creased significantly (-O.g + 1.4 mmol/|, p < 0.05) in DE and
increased significantly (+0.+ + 0.5 mmol/|, p < 0.05) in D.
Maximum exercise performance improved significantly
(+lZ.Z + 8.8 W p < 0.05) in DE and did not change signifi-
cantly in D. Conclusions.'This study showed that indepen-
dently of the method for weight loss, the negative energy
balance alone is responsible for weight reduction.
Copyright o 2007 5. Karger AG, Basel
Introduction
Obesity is the result of excess energy intake compared
to energy expenditure. To lose weight, a negative energy
balance must be evoked [1]. Dietary restriction and exer-
cise are useful methods to create a negative energy bal-
ance. However, the existent literature appears to provide
little evidence that exercise alone is a potent strategy for
loss of body mass (BM). The lack of efficacy for exercise
to promote BM loss may be in part due to the relatively
Ann Nutr Metab 2007;51:428-432
DOI: 1 0.1 1 59/0001 1'l 162
Fat Loss Depends on Energy
Deficit Only, lndependently of the
Method for Weight Loss
B. Strasseru A. Spreitzerb P. Habera
aDepartment of lnternal Medicine lV Division of Sports Medicine, Medical University Vienna, and
blnstitute of Nutritional Sciences, University of Vienna, Vienna, Austria
KARGER
Fil +41 61 306 12 34
E-Mai1 karger@kargerch
rmw.kargercom
O 2007 S. Karger AG, Basel
0250 - 6807 I 07 I 0515 0428$23.s0/0
Accessible online at:
www.karger.com/anm
Dr. Barbara Strasser
Zentrum für medizinische Trainingstherapie und Trainingsberatung
Roetzergasse 41l1, AT 1170 Vienna (Austria)
Tel. +43 t 485 8164 11, Fax +43 1 485 8164 13
E-Mail barbara.strasser@trainingstherapie.at
low amount that has been used in exercise studies. Ross
et al. showed that the energy expenditure ofexercise has
to be between 2,000 and 3,000 ki per day to provide a BM
loss of approximately 6 kg in women l2l and 8 kg in men
[3] within 12 weeks. Similarly, in findings by Donnelly et
al. [4], with increased levels of energy expenditure of ex-
ercise, loss of BM was shown in men but to a lesser extent
in women. Fogelholm [5] reviewed the effects of walking
(150-225 min/week) on BM reduction in obese partici-
pants with or without a low-energy diet (5,000 -7,000k|l
day). The mean BM reduction during 3-6 months when
walking was added to diet was numerically (by 0.3-2.1
kg) but not significantly better than the diet-only group.
Utter et al. [6] measured the influence of diet (5,000-
5,500 kl/dar, exercise (225 minlweek at 78.5 + 0.5o/o
maximum heart rate) or both on body composition and
cardiorespiratory fitness in obese women. The results in-
dicated that moderate aerobic training during a l2-week
v period had no discernible effects on body composition
but improved cardiorespiratory fitness in dieting obese
women. Serum cholesterol and triacylglycerol improved
in both diet and in exercise plus diet groups after 12 weeks
of intervention and was most strongly related to BM loss
[7]. Himeno et al. [8] evaluated the effects of exercise and
a mild hypocaloric diet on cardiovascular risk factors in
obese subjects. After 12 weeks, a combination of aerobic
exercise and a mild hypocaloric diet significantly con-
tributed not only to the loss of BM but also to the im-
provement of dyslipidemia and exercise performance, but
either hypocaloric diet or mild exercise independently
had less effects.
Thus, there is strong evidence that hypocaloric diets
and physical activity can induce loss of BM in obese pa-
tients. Nutrition therapy and increased physical activity
improve obesity-associated risk factors and can prevent
. or delay comorbidities [9].
\-/ The above-mentioned studies suggest that exercise ac-
tivity alone reduces BM only slightly and that only the
combination of both, diet and training, leads to signifi-
cant BM reduction. Moreover, exercise activity reduces
the diet-induced loss of fat-free mass and favors BM re-
duction through an increased metabolic rate [10]. Unfor-
tunately, most of the exercise studies for BM reduction
did not measure the total caloric deficit and its correla-
tion with the loss of BM.
The new aspect of our study is that fat loss is exclu-
sively determined by the amount of the energy deficit in-
dependently of the method achieving the negative energy
balance. Therefore, we compared the effects of a negative
balance by 1,680 k| per day, once obtained by diet alone
and once composed of diet and aerobic training, on body
composition, blood lipid profile and cardiorespiratory
fitness in non- and moderately obese women.
Methods
Study Population
We recruited 20 non- or moderately obese (BMl 24.32 + 3.11)
females (22.5 + 6.6 years) through advertisements from the sur-
rounding community. Subjects were randomly divided into either
a diet alone (D, -1,680 kl/day) or a diet (-840 kl/da, plus exercise
(DE, three 60-min sessions per week at 60%o of VO2max or -840
kl/da, group. Measurements of energy intake, body composition,
serum lipids and cardiorespiratory fitness were conducted in all
subjects before and after an 8-week exercise and/or energyrestric-
tion intervention period.
Dietary Program
Prior to the study, all subjects kept a 3-day food record. Sub-
jects ofD were placed on a 1,680- and subjects ofDE on an 840-kf
caloric deficit per day. Subjects were instructed on portion sizes
and how to record dietary intake using a daily dietary protocol.
Compliance with the diet was measured in all subjects byrandom,
weekly, 24-how dietary recalls. Nutrient intake from the 3-day
food records and 24-hour dietary recalls was assessed using a
computerized dietary analysis system (WVG software, Prodi@,
version 4.5 LE compact+). The dietary menu was based on 25 en-
ergy percent fat, 55-60 energy percent carbohydrates and 15-20
energy percent proteins.
Training Program
To reach an isocaloric energy reduction, subjects in the DE
group were required to walk or run 3 times a week under supervi-
sion of a trainer, 60 min per session (in dependence on physical
fitness), at600/o of YO2max, for 8 weeks. Exercise heart rates were
measured with chest heart rate monitors (Polar@). The net energy
expenditure during exercise was derived by using the following
formula [11]: 4.19 kf per kg BM per km.
Fitness and Status of Blood Lipids
Body Mass Index.Eachparticipant had her bodyweight (Tani-
ta@ BWB-620, to the nearest 0.1 kg) and height (to the nearest 0.1
cm) recorded while wearing light indoor clothes but no shoes. BM
was tested before and after the study, with weekly weigh-ins con-
ducted for all subjects during the B-week intervention.
Body Fat. During the week prior to and at the end of the 8-
week study, all subjects were tested for body fat (in percent of
body weight) using the bioelectrical impedance analysis method
(Omron@ BF 302).
Serum Lipids. Venous blood was drawn after overnight fast-
ing. Serum total cholesterol, high-density lipoprotein cholesterol
(HDL-C), low-density lipoprotein cholesterol (LDL-C) and tri-
glycerides were measured before and after the studyby the clinical
laboratory of the Medical University Vienna. Samples were ana-
lyzed on the day they were collected.
Maximal Aerobic Power. Prior to and at the end of the 8-
week study, all subjects underwent a cycling test on an electri-
cally braked cycle ergometer (Ergoline@ Ergometrics 900) to the
Fat Loss Depends Only on Energy Deficit Ann Nutr Metab 2007;51:428-432 429
Table '1. Subject characteristics and treatment regimens at base-
line (mean + SD)
Characteristics and regimens Diet plus
exercise
Age, years 25.8+ 6.9 ZB.B+ 6.4 n.s.
Body mass, kg 67.2+ 9.4 68.6 + 6.6 n.s.
Body mass index 23.9 + 3.8 24.7 + 2.4 n.s.
Body fat, 7o 24.6 + 6.9 27.1 + 6.0 n.s.
Energyintake,kJlday 9,704+ t,920 9,574+ I,535 n.s.
Cardiorespiratory fitness, W 161.8 + 26.1 165.9 + 32.t n.s.
Table 2. Effect ofexercise training and energy restriction on body
composition and cardiorespiratory endurance over 8 weeks in 20
non- or moderately obese females (mean + SD)
Table 3. Effect ofexercise training and energy restriction on se-
rum lipids over 8 weeks in 20 non- or moderately obese females
(mean + SD)
Diet
(n = 10) Diet plus
exercise
(n = 10)
p
value
Cholesterol, mg/dI
Before study
After study
HDL-C, mg/dl
Before study
After study
LDL-C, mg/dl
Before study
After study
Triglycerides, mg/di
Before study
After study
173.7 + 28.5 208.5 + 40.4 >0.05
1.79.9 + 24.5 208.4+ 35.9
64.2+ t3.3
61.5 + 8.8
89.9 + 28.3
93.3 + 25.3
97.7 + 40.5
104.9 + 54.7
65.4+ 77.8 >0.05
66.5 + t2.3
t24.4+ 34.2 >0.05
t23.5 + 33.8
93.9 + 30.4 >0.05
92.6 + 26.9
Heart rate (l/min) submaximal exertion, 100 W
p < 0.05, statistically significant.
Results
Statistical analysis was performed using the statistical
computer software SPSS (Statistical Package for Social
Sciences, SPSS Inc., Chicago, I11., USA;version 11.0). The
arithmetic mean and the standard deviation were calcu-
lated for all data. p values (0.05 were considered statisti-
cally significant. In order to exclude significant differ-
ences between the groups prior to the study, the indepen-
dent-sample t test was used. To document changes of
several variables between the first and the second test, the
paired t test and the Shapiro-Wilk test were applied. To
compare the 2 groups at the end of the study, the 2-sample
t test was used.
At study entry, D and DE groups had similar profiles
for all parameters (table 1). Prior to the study, 3-day food
records indicated a caloric intake of 9,704 + 1,920 and
9,574 + 1,535 kf/day for the D and DE group, respective-
ly. Subjects of D decreased the energy intake on a2,095
+ 638 k|, subjects of DE on a 1,420 + 1,084 kl caloric
deficit per day, respectively. Together with the energy ex-
penditure by exercise, DE had a daily energy deficit of
1,982 + 595 kllday. This was not significantly different
from D.
Body composition and cardiorespiratory endurance
are summarized in table 2. BM and body fat decreased
significantly (-Z.t + 1.2 kg or -1.53 + 0.87o/o; p < 0.05)
Diet
(n = l0) Diet pius
exercise
(n = 10)
Body mass, kg
Before study
After study
Body mass index
Before study
After study
Body fat,o/o
Before study
After study
Cardiorespiratory fi tness, Wmax
Before study
After study
Before studv
After studv
Before study
After study
Lactate (mmol/l) submaximal exertion, 100 W
67.2+ 9.4
65.2+ B.7x
23.9 + 3.8
23.3 + 3.6
24.6+ 6.9
23.t+ 6.8
76t.8 + 26.t
754.5 + 24.6
t49.3+ 14.5
150.5 + 13.5
3.9 + 1.1
4.3+ 1.2x
68.6+ 6.6
66.4+ 6.6x
24.7 + 2.4
23.9 + 2.4
27.1 + 6.0
25.5+ 6.2*
165.9 + 32.t
178.1 + 37.6x
t45.7 + t6.5
t41.8+ 20.4
4.0+ t.7
3.2 + 0.gx
x p < 0.05, statistically significant.
point of exhaustion. Heart rate was continuously monitored via
an electrocardiogram, with blood pressure measured in the final
minute of each work level. Exercise started with a work load of
50 W and was increased stepwise by 25 W every 2 min until ex-
haustion. The following parameters were determined: maximal
power (in watt), maximal heart rate, heart rate and lactate during
submaximal exertion (100 W). Capillary blood was drawn from
the earlobe and analyzed for lactate (Eppendorf@ E SAT 6661 Lac-
tat) at rest, in the final minute of each work level and 3 min after
exhaustion.
430 Ann Nutr Metab 2007;51:428-432 Strasser /Spreitzer I }Iab er
in both groups (D+DE), but there was no significant dif-
ference observed between the groups. Subjects in D and
DE lost 1.95 + 1.13 and 2.23 + 1.29 kg BM and 1.47 +
0.87 and 1.59 + 0.87o/o body fat, respectively, during
the study. Lactic acid accumulation during submaxi-
mal exertion (100 W) decreased significantly (-0.8 + 1.4
mmol/I, p < 0.05) in DE and increased significantly (+0.4
+ 0.5 mmol ll,p <0.05) in D. Maximum exercise perfor-
mance improved significantly (+12.2 + 8.8 W p < 0.05)
in DE and did not change significantly in D. We found no
significant changes of heart rate during submaximal ex-
ertion (100 W). Table 3 summarizes the serum lipid data.
Statistical analysis revealed no significant changes ofto-
tal cholesterol, HDL-C, LDL-C and triglycerides for both
groups.
Discussion
In this randomized, controlled 8-week study of a group
of 20 non- or moderately obese women, energy restriction
alone or in combination with aerobic training signifi-
cantly lowered BM and percent body fat. Serum lipids and
heart rate during submaximal exertion did not change in
either group, while lactic acid accumulation during sub-
maximal exertion decreased and maximum exercise tol-
erance improved significantly in the diet plus exercise
group.
This study showed that independently of the method
for BM loss, the negative energybalance alone is respon-
sible for BM reduction. The mean loss of BM of 1.95 +
1.13 kg in the diet group was nearly identical to 2.23 +
1.29 kg in the diet plus exercise group. Further, we did not
find any significant difference in fat loss between the
groups (1.+Z + 0.87 and 1.59 + 0.87o/o for the diet and
diet plus exercise group, respectively).
Therefore, to lose body fat, more calories have to be
expended than consumed at the end of the day. However,
most of the exercise studies suggest that exercise activity
alone has only a minor influence on fat reduction and
that mainly the combination of both, diet and exercise
training, leads to significant reduction of BM. Unfortu-
nately, the classic explanation for the secondary role of
exercise is that exercise alone cannot generate enough en-
ergy expenditure to create a negative energy balance to
the extent possible with energy restriction. Ross et al. [2]
stated that the energy expenditure of exercise has to be
between 2,000 and 3,000 kl per day to provide a BM loss
of approximately 6 kg for women within 12 weeks. This
is true but it is also true that a negative energy balance of
2,500-3,350kllday always causes a fat loss of 6-8 kg with-
in 3 months [84 days x 2,500 klldayl39,900 k/kg fat =
5.3 kg fat loss - this is comparable with a BM loss of 6 kgl.
These studies for BM reduction did not measure the total
caloric deficit and its correlation with the loss of BM. In
fact, the amount of fat reduction simply depends on ca-
loric deficit, independently of the method for BM loss.
Numerous studies and reviews have concluded that
moderate exercise training has little effect on total cho-
lesterol or LDL-C unless combined with weight loss or
change in dietary quality [12].In our study, a mild hypo-
caloric diet with or without aerobic training was insuf-
ficient to stimulate changes in lipid profile. The reason
could be explained by the young study population (27.3
+ 6.6 years) with nearly normal B}iII (24.32 + 3.11) and
blood lipid profile.
The effectiveness of aerobic training in the diet plus
exercise group was shown by a12.2 + 8.8 watt improve-
ment in cardiorespiratory fitness and a 0.8 + 1.4
mmol/l reduction of lactic acid accumulation during sub-
maximal exertion, while in the diet-only group cardiore-
spiratory fitness decreased by 7.3 + 12.9 W and lactic
acid accumulation during submaximal exertion increased
significantly by 0.4 + 0.5 mmol/I.
Conclusion
This study showed that reduction of body fat simply
depends on energy deficit, and that independently ofthe
method for body fat loss solely a negative energybalance
is responsible for the amount of body fat reduction. Diet
combined with aerobic training has the benefit of a gain
in physical fitness in addition to fat loss.
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432 Ann Nutr Metab 2007;5L:428-432 Strasser /Spreit zer I Haber
... From this authors point of view, it appears to be that the simplicity of this idea may be the crux for its continued use. Yet, the rationale has several logical flaws that hamper its overall justification for altering or maintaining body mass [11,12,14,20,21]. The first ...
... Moreover, we understand that metabolic changes associated with changes in nutrition and increased activity tend to reverse many of the health issues associated with overfatness [2][3][4][5][6]. So much so, that over the last half-century the use diet and exercise to prevent many non-communicable diseases (e.g., diabetes and metabolic syndrome, cardiovascular disease, cancer) associated with overfatness and has become cornerstone of therapy for ameliorating issues of overfatness that lead to the non-communicable diseases [1,[6][7][8][9][10][11][12]. ...
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... A higher VO₂max is associated with reduced risks of cardiometabolic disorders, including hypertension, dyslipidemia, and type 2 diabetes [15,16,17]. Conversely, low VO₂max levels are predictive of increased morbidity and mortality related to noncommunicable diseases [16]. Enhancing VO₂max and improving body composition through structured exercise, such as HIIT, has garnered significant research interest. ...
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Purpose: This study aimed to characterize the association between microbial dynamics and excessive exercise. Methods: Swabbed fecal samples, body composition (percent body fat), and swimming logs were collected (n = 94) from a single individual over 107 days as he swam across the Pacific Ocean. The V4 region of the 16S rRNA gene was sequenced, generating 6.2 million amplicon sequence variants. Multivariate analysis was used to analyze the microbial community structure, and machine learning (random forest) was used to model the microbial dynamics over time using R statistical programming. Results: Our findings show a significant reduction in percent fat mass (Pearson; p < 0.01, R = −0.89) and daily swim distance (Spearman; p < 0.01, R = −0.30). Furthermore, the microbial community structure became increasingly similar over time (PERMANOVA; p < 0.01, R = −0.27). Decision-based modeling (random forest) revealed the genera Alistipes, Anaerostipes, Bifidobacterium, Butyricimonas, Lachnospira, Lachnobacterium, and Ruminococcus as important microbial biomarkers of excessive exercise for explaining variations observed throughout the swim (OOB; R = 0.893). Conclusions: We show that microbial community structure and composition accurately classify outcomes of excessive exercise in relation to body composition, blood pressure, and daily swim distance. More importantly, microbial dynamics reveal the microbial taxa significantly associated with increased exercise volume, highlighting specific microbes responsive to excessive swimming.
... As the inappropriate feedback coming from body weight changes can serve as an aversive stimulus or punishment (Clark, 2018;Greaves et al., 2011;Lavoie et al., 2017;Locke and Latham, 2006) and hinder continuation in any programme, even if improvements in fitness may be present (Booth and Laye, 2009;Clark, 2016;Duncan et al., 2011;Ekkekakis and Lind, 2006;Hafekost et al., 2013;Hall, 2013;Thomas et al., 2008). Thus, necessitating supervision that results in a sense of coercion to continue the programme, as well as the negative psychological ramifications associated with the perceived lack of self-management required by the individual to attain long-term success with the intervention (Bacon and Aphramor, 2011;Bamman et al., 2014;Booth et al., 2012;Clark, 2012Clark, , 2016Hafekost et al., 2013;Sidman, 1993;Strasser et al., 2007). This lack of self-monitored or self-selected behavioural control allows for short-term changes to be briefly met and typically followed by rapid and exaggerated reversals (Bandura, 2004;Clark, 2012Clark, , 2016Hall, 2013;Hooper et al., 2010;Locke and Latham, 2006;Outland and Stoner-Smith, 2013). ...
... Beyond this, and even though hypertrophic intensities have been indicated as being more effective, resistance exercise recommendations tend to be at lower than hypertrophic intensities and closer to what is more readily used for muscle endurance. Finally, programmes tend to focus on weight loss by establishing a caloric deficit through increased expenditures and combined with exercise at an intensity intended to increase fat oxidation (Hall, 2008;Strasser et al., 2007;Thomas et al., 2013). This focus leads programmes to fail to establish an intrinsic drive toward exercise or the hormonal modifications necessary to reduce fat mass and improve health status in the longterm (Clark, 2012;Clark and Goon, 2015). ...
Article
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.
... Therefore, as a means to further explore cardiovascular disease risk as a result of an obese state in the absence of co-morbidities associated with obesity (such as diabetes, insulin resistance), this systematic review hopes to focus on metabolically healthy obese adults which include a subgroup of obese adults who do not exhibit overt cardiometabolic abnormalities such as diabetes, or hypercholesterolemia. 5 Furthermore, weight loss is associated with improving lipid profiles 6 and therefore obese participants may experience more balanced lipid profiles when undergoing weight reduction, as through dietary energy deficits. 7 However, in the context of hypocaloric diets, hunger has been noted as one of the primary issues in obese participants compliance to weight-loss diets. 8 A clinical trial noted that hypocaloric, high-protein diets significantly lower food cravings, and improve mood in obese participants. ...
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Introduction: This systematic review has been undertaken in order to assess the effects of hypocaloric, high- protein diets on weight loss and cardiovascular risk factors such as serum lipid levels in metabolically healthy obese adults. The primary outcomes measured include changes in pre-and post- diet mean BMI, LDL-C, HDL-C, TAG, and TC levels. Methods: Four databases including: Embase, MEDLINE (via PubMed), Cochrane and Web of Science were searched with no restrictions on language or publication period. Clinicaltrials.gov was also searched in order to identify unpublished or on-going studies. Results: Three of four studies included in this systematic review noted a significantly greater loss in pre- and post- diet mean BMI levels in the hypocaloric, high-protein diet group as compared to hypocaloric, non-high protein diets (control). Whilst pre- and post-diet mean LDL-C, HDL-C, TAG, and TC levels did not differ significantly among hypocaloric, high-protein and control diet groups. Conclusion: Hypocaloric, high-protein diets had an unclear effect on blood-lipid levels as compared to control. Weight loss however was significantly greater in the hypocaloric, high-protein group as compared to other hypocaloric, non-high-protein diet groups.
... Even though losing weight is considered simple, it is not easy. Its simplicity relies in the logic of consuming fewer calories than spending, i. e., seek a negative caloric balance (FREEDMAN et al., 2001;JOHNSTON et al., 2014;STRASSER et al., 2007). ...
Conference Paper
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There are diverse reasons for weight loss, from aesthetic issues to medical needs. The world is experiencing an obesity epidemic, evidenced by a global increase in trending cases, so must be treated as a public health problem. Although the requirement for weight loss is consuming consistently fewer calories than you burn over time, there are confusion and conflicting information on how to go about doing this. It occurs in a dynamic and changeable environment, involving behavioral, psychological, and motivational aspects. Obstacles appear along the way, making adherence difficult. There is no structured and systematic way in the literature to approach this process scientifically. The objective of this article is to propose a systematic model for weight loss management, applying the improvement kata approach. As for the research methods, was made a qualitative research, with bibliographic search consulting databases MEDLINE(Pubmed), SCOPUS, Artigo Completo 2 Emerald, and books, guiding the model's construction. Using information technology, 9 experts with experience in different areas received an explanatory text for the model evaluation. The analysis' consolidation shows 100% consensus regarding the model's consistency, with 44% claiming using something similar in their practice. Therefore, this study evidences a structured and systematic approach for weight loss management.
... A sustained negative energy balance (EB) is essential for weight loss to occur [1][2][3]. While both exercise and dietary restrictions can be used to induce an energy deficit, they do not seem to induce the same adaptive responses for appetite [4]. ...
Article
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Sleep is bi-directionally linked to energy balance. This crossover study design will evaluate the acute effect of a moderate energy deficit (500 kcal) induced by diet, exercise, or mixed (−250 kcal by diet and 250 kcal by exercise) on sleep and the next morning’s appetitive responses. The study sample comprises 24 healthy young adults. The experimental measurements will be conducted in a naturalistic, momentary manner and partly assessed by the participants. The participants will undergo a run-in period in order to stabilize their sleep schedules and provide them with training on the study protocol and measurements. Indirect calorimetry will be used to determine their resting metabolic rate and peak oxygen consumption (VO2 peak). Then, they will take part in a control session (CTL), followed by three energy deficit sessions in random order: a diet-induced energy deficit session (DED), an exercise-induced energy deficit session (EED), and a mixed energy deficit session (MED). All experimental sessions will be separated by a one-week washout. The participants’ sleep will be monitored by ambulatory polysomnography, and the next morning’s appetitive response will be evaluated via ad libitum food intake, appetite sensations, and food reward, measured by a food liking and wanting computerized test.
... These results could be explained by the fact that, although the adolescents have an optimal AMD, the level of physical activity in the overweight group is very low (≤2.75). Thus, most of the adolescents in this group are considered physically inactive, which would make it difficult to achieve the caloric deficit necessary to reduce body fat [41]. However, the results obtained should be taken with caution, as the sample size of the overweight groups of males and females was very small, which makes it difficult to extrapolate the results. ...
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The present investigation provides a new paradigm, the fat but healthy diet, through which to analyze the importance of adherence to the Mediterranean diet (AMD) in the adolescent population. To this end, the objectives were to analyze the existing differences in physical fitness, level of physical activity, and kinanthropometric variables in males and females with different AMD and to determine the existing differences in physical fitness, level of physical activity, and kinanthropometric variables in adolescents with different body mass index and AMD. The sample consisted of 791 adolescent males and females whose AMD, level of physical activity, kinanthropometric variables, and physical condition were measured. The results showed that when analyzing the whole sample, the differences were only significant in the level of physical activity among adolescents with different AMD. However, when considering the gender of the adolescents, the males also showed differences in the kinanthropometric variables, while the females did so in the fitness variables. In addition, when considering gender and body mass index, the results showed that overweight males with better AMD showed less physical activity and higher body mass, sum of three skinfolds, and waist circumference, and females did not show differences in any variable. Therefore, the benefits of AMD in anthropometric variables and physical fitness of adolescents are questioned, and the fat but healthy diet paradigm cannot be confirmed in the present research.
... Therefore, as a means to further explore cardiovascular disease risk as a result of an obese state rather than cardiovascular disease risk as a result of the co-morbidities associated with obesity, this systematic review hopes to focus on metabolically healthy obese adults which include a subgroup of obese adults who do not exhibit overt cardiometabolic abnormalities such as diabetes, or hypercholesterolemia . Furthermore, weight loss is associated with a decrease in the aforementioned lipid levels (Van Gaal, Mertens and Ballaux, 2005) and therefore obese participants may experience more balanced lipid profiles when undergoing weight reduction, as through dietary energy deficits (Strasser, Spreitzer and Haber, 2007). However, in the context of hypocaloric diets, hunger has been noted as one of the primary issues in obese participants compliance to weight-loss diets (LaPorte and Stunkard, 1990). ...
Preprint
Background: This systematic review has been undertaken in order to assess the effects of hypocaloric, high-protein diets on weight loss and cardiovascular risk factors such as serum lipid levels in metabolically healthy obese adults. The primary outcomes measured include changes in pre- and post- diet mean BMI, LDL-C, HDL-C, TAG, and TC levels. Method: Four databases including: Embase, MEDLINE (via PubMed), Cochrane and Web of Science were searched with no restrictions on language or publication period. Clinicaltrials.gov was also searched in order to identify unpublished or on-going studies. Results: Three of four studies included in this systematic review noted a significantly greater loss in pre- and post- diet mean BMI levels in the hypocaloric, high-protein diet group as compared to hypocaloric, non-high protein diets (control). Whilst pre- and post-diet mean LDL-C, HDL-C, TAG, and TC levels did not differ significantly among hypocaloric, high-protein and control diet groups. Conclusion: Hypocaloric, high-protein diets had an unclear effect on blood-lipid levels as compared to control. Weight loss however was significantly greater in the hypocaloric, high-protein group as compared to other hypocaloric, non-high-protein diet groups.
... Para o controle e perda de peso, mudanças de hábito, como intervenções dietéticas e atividades físicas, são estratégias eficazes para reduzir o consumo calórico e promover um balanço energético negativo (Strasser et al., 2007;Yin et al., 2021). O jejum intermitente, caracterizado pela redução ou restrição de calorias, diminui o ganho de peso por meio da promoção do déficit calórico. ...
Article
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O objetivo deste estudo foi avaliar a associação entre o jejum intermitente (IF) e a ingestão de café em ratos Wistar pré-tratados com dieta hiperlipídica. Foram utilizados ratos Wistar, recém-nascidos, distribuídos aleatoriamente em 4 grupos: Controle (CO, Ração comercial), Controle+Café (CA, ração comercial+café), Jejum (IF, 24 horas alimentação/24 horas de jejum), Jejum+Café (IFCA, 24 horas alimentação/24 horas jejum+café). Os animais foram pré-tratados com dieta hiperlipidica por 30 dias. O café administrado nos animais foi 100% Arábica, na dose de 0,5 mL por gavagem diariamente. O peso foi aferido semanalmente durante todo o experimento e após a eutanasia foram retiradas e pesadas as gorduras subcutâneas e visceral. Foram analisadas as taxas de glicose e insulina, perfil lipídico e a histologia hepática. Os grupos que fizeram jejum apresentaram resultados significativamente menores no ganho de peso e de massa gorda, melhor perfil lipídico e menor deposição de gordura hepática. Observou-se menor deposição de colágeno nos grupos que ingeriram café, assim com um menor teor de umidade. A partir dos resultados obtidos, pode-se concluir que a associação das intervenções pode ser benéfica na redução de ganho de peso e de gordura corporal, além de apresentar efeito sinérgico na redução da esteatose hepática em ratos pré-tratados com dieta hiperlipídica.
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The purpose of this study was to measure the influence of diet, exercise, or both on body composition and cardiorespiratory fitness in obese women. Ninety-one obese subjects were randomized into one of four groups: diet (D) (4.19-5.44 MJ or 1,200-1,300 kcal/day), exercise (E) (five 45-min sessions at 78.5+/-0.5% maximum heart rate), exercise and diet (ED), and controls (C). Maximal aerobic power and body composition were measured in all subjects before and after a 12-week diet intervention period. Subjects in D and ED lost 7.8+/-0.7 and 8.1+/-0.6 kg body mass, with no significant change for E relative to C. Losses of percent body fat and fat mass were significantly greater in D and ED but not in E relative to C. The change in VO2max was greater in ED and E but not D when compared to C. Results indicate that moderate aerobic exercise training during a 12-week period has no discernible effects on body composition but does improve cardiorespiratory fitness in dieting obese women.
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The independent effects of diet- or exercise-induced weight loss on the reduction of obesity and related comorbid conditions are not known. The effects of exercise without weight loss on fat distribution and other risk factors are also unclear. To determine the effects of equivalent diet- or exercise-induced weight loss and exercise without weight loss on subcutaneous fat, visceral fat skeletal muscle mass, and insulin sensitivity in obese men. Randomized, controlled trial. University research center. 52 obese men (mean body mass index [+/-SD], 31.3 +/- 2.0 kg/m2) with a mean waist circumference of 110.1 +/- 5.8 cm. Participants were randomly assigned to one of four study groups (diet-induced weight loss, exercise-induced weight loss, exercise without weight loss, and control) and were observed for 3 months. Change in total, subcutaneous, and visceral fat; skeletal muscle mass; cardiovascular fitness; glucose tolerance and insulin sensitivity. Body weight decreased by 7.5 kg (8%) in both weight loss groups and did not change in the exercise without weight loss and control groups. Compared with controls, cardiovascular fitness (peak oxygen uptake) in the exercise groups improved by approximately 16% (P < 0.01). Although total fat decreased in both weight loss groups (P < 0.001), the average reduction was 1.3 kg (95% CI, 0.3 to 2.3 kg) greater in the exercise-induced weight loss group than in the diet-induced weight loss group (P = 0.03). Similar reductions in abdominal subcutaneous, visceral, and visceral fat-to-subcutaneous fat ratios were observed in the weight loss groups (P < 0.001). Abdominal and visceral fat also decreased in the exercise without weight loss group (P = 0.001). Plasma glucose and insulin values (fasting and oral glucose challenge) did not change in the treatment groups compared with controls (P = 0.10 for all comparisons). Average improvement in glucose disposal was similar in the diet-induced weight loss group (5.6 mg/kg skeletal muscle per minute) and in the exercise-induced weight loss group (7.2 mg/kg skeletal muscle per minute) (P > 0.2). However, these values were significantly greater than those in the control and exercise without weight loss groups (P < 0.001). Weight loss induced by increased daily physical activity without caloric restriction substantially reduces obesity (particularly abdominal obesity) and insulin resistance in men. Exercise without weight loss reduces abdominal fat and prevents further weight gain.
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The purpose of this study is to review the effects of aerobic exercise training (AET) on blood lipids and assess dose-response relationships and diet interactions. We reviewed papers published over the past three decades pertaining to intervention trials on the effects of > or = 12 wk of AET on blood lipids and lipoprotein outcomes in adult men and women. Included were studies with simultaneous dietary and AET interventions, if they had appropriate comparison groups. Studies were classified by the participants' relative weights expressed as mean BMIs. Information was extracted on baseline characteristics of study subjects, including age, sex, and relative baseline cholesterol levels; details on the training programs; and the responses to training of body weight, VO(2max), and blood total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), and triglyceride (TG). We identified 51 studies, 28 of which were randomized controlled trials. AET was generally performed at a moderate to hard intensity, with weekly energy expenditures ranging from 2,090 to >20,000 kJ. A marked inconsistency was observed in responsiveness of blood lipids. The most commonly observed change was an increase in HDL-C (with reductions in TC, LDL-C, and TG less frequently observed). Insufficient data are available to establish dose-response relationships between exercise intensity and volume with lipid changes. The increase in HDL-C with AET was inversely associated with its baseline level (r = -0.462), but no significant associations were found with age, sex, weekly volume of exercise, or with exercise-induced changes in body weight or VO(2max). Moderate- to hard-intensity AET inconsistently results in an improvement in the blood lipid profile, with the data insufficient to establish dose-response relationships.
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This study was designed to measure the influence of diet, exercise or both on serum lipids and lipoproteins in obese women. Obese subjects were randomly divided into one of four groups: diet alone (1,200-1,300 kcal/day, NCEP, Step I), exercise alone (five 45 minute sessions per week at 78.4+/-0.5% maximum heart rate), exercise and diet, and controls. Maximal aerobic power, body composition, diet, serum lipids and lipoproteins were measured in all subjects at baseline and after a 12-week intervention period. Subjects included 91 moderately obese (45.6+/-1.1 y, body mass index 33.1+/-0.6 kg/m2) and 30 nonobese (43.2+/-2.3 y, body mass index 21.4+/-0.34 kg/m2) women who were recruited from the surrounding community. Independent t tests were used to compare obese and nonobese subjects at baseline. The 12-week intervention data from the obese groups were analyzed using a 4 x 2 repeated measures ANOVA design. Cross-sectional comparisons at baseline showed obese subjects had significantly higher total cholesterol, triacylglycerol. total cholesterol/HDL-C and LDL-C values and lower HDL-C values. Prospective results showed that subjects in diet and exercise and diet lost 7.8+/-0.7 and 8.1+/-0.6 kg body mass, with no significant change for exercise relative to control. Serum cholesterol and triacylglycerol improved in both diet and in exercise and diet after 12 weeks of intervention, and was most strongly related to weight loss. Weight loss is the most effective means of reducing lipid and lipoprotein risk factors in obese women.
Article
Background: The independent effects of diet- or exercise-induced weight loss on the reduction of obesity and related comorbid conditions are not known. The effects of exercise without weight loss on fat distribution and other risk factors are also unclear. Objective: To determine the effects of equivalent diet- or exercise-induced weight loss and exercise without weight loss on subcutaneous fat, visceral fat, skeletal muscle mass, and insulin sensitivity in obese men. Design Randomized, controlled trial. Setting: University research center. Participants: 52 obese men (mean body mass index [±SD], 31.3 ± 2.0 kg/m 2 ) with a mean waist circumference of 110.1 ± 5.8 cm. Intervention: Participants were randomly assigned to one of four study groups (diet-induced weight loss, exercise-induced weight loss, exercise without weight loss, and control) and were observed for 3 months. Measurements: Change in total, subcutaneous, and visceral fat; skeletal muscle mass; cardiovascular fitness; glucose tolerance and insulin sensitivity. Results: Body weight decreased by 7.5 kg (8%) in both weight loss groups and did not change in the exercise without weight loss and control groups. Compared with controls, cardiovascular fitness (peak oxygen uptake) in the exercise groups improved by approximately 16% (P 0.2). However, these values were significantly greater than those in the control and exercise without weight loss groups (P < 0.001). Conclusions: Weight loss induced by increased daily physical activity without caloric restriction substantially reduces obesity (particularly abdominal obesity) and insulin resistance in men. Exercise without weight loss reduces abdominal fat and prevents further weight gain.
Article
Walking during weight reduction leads to modest weight loss, abdominal fat loss, and total fat loss. The response is barely observable at a prescribed level of 150-200 min/wk. Hence, 250-300 min/wk (or 35-45 min daily) seems more suitable for weight reduction purposes. The walking can be split into shorter (10-20 min) periods. There is a dose response between the amount of completed physical activity and weight-loss maintenance. An exercise energy expenditure of 9-10 MJ/wk (2200-2400 kcal), corresponding to walking 70-80 min/day, seems to be associated with stable weight after weight reduction. A smaller amount of walking may slow down, although not prevent, weight regain. Walking studies among people with obesity do not clearly show improvements in lipids or insulin sensitivity. Meta-analyses, including all kinds of physical activities, have shown positive changes in high-density lipoprotein-cholesterol (HDL-C) levels and insulin sensitivity. The amount of exercise, in the absence of weight loss, corresponding to improvements of insulin sensitivity, is around 4.2 MJ/wk (walking 150-180 min/wk). A greater amount of exercise may be needed to improve lipoprotein profiles. The minimum recommended amount of walking for the management of obesity, which is 150-200 min/wk (25-30 min/day or 3500 steps/day added above the basal, sedentary daily activity of 5000-7000 steps/day), may improve insulin sensitivity and cardiorespiratory fitness; however, a significant effect on weight should not be expected. Increasing the duration of walking to 250-300 min/wk (35-45 min/day or 5000 added steps/day) should lead to beneficial changes in weight and HDL-C. Much more than 300 min/wk of walking may be needed to prevent weight regain after substantial weight loss. Cross-sectional studies suggest that a combination of walking and vigorous exercise activity is optimal for weight management and the prevention of cardiovascular deaths. Moreover, individuals who are able to maintain their weight loss long-term expend almost 30% of physical activity energy in vigorous activities. Perhaps high-intensity activities are also needed to increase the total physical activity to efficacious levels for the management of obesity.
Article
A meta-analysis was performed to examine how exercise training and gender influence the composition of diet-induced weight loss. The groups did not differ with respect to either the amount of body weight lost (mean = -10 +/- 1.4 kg) or fat mass lost (mean = -8 +/- 1.1 kg). However, exercise training significantly (P < 0.05) reduced the amount of body weight lost as fat-free mass compared to dietary restriction only (DO) for the same sex. The percentage of weight lost as fat-free mass for diet-plus-exercise (DPE) subjects was approximately half (P < 0.05) of that for DO subjects of the same sex (DO males = 28 +/- 4% of weight lost as fat-free mass; DPE males = 13 +/- 6%, DO females = 24 +/- 2%, DPE females = 11 +/- 3%). These data provide evidence that exercise training reduces the amount of body weight lost as fat-free mass during diet-induced weight loss. In addition, sex differences do not seem to exist with respect to the composition of diet-induced weight loss.
Article
A weight reduction program to improve cardiovascular risk factors was implemented in obese subjects. The program consisted of exercise training corresponding to the anaerobic threshold (AT) and a mild hypocaloric diet for 12 weeks. In this program, we evaluated the effects of a combination of exercise training and a diet on cardiovascular risk factors such as obesity, dyslipidemia, and poor exercise performance in obese subjects. In addition, we also evaluated the independent effects of exercise training and dietary modification. For this purpose, we adopted a relative training time and a diet score. A relative training time was calculated as the number of times that the subject performed exercises divided by all of the training sessions scheduled, and the diet score was calculated from information which each subject provided on a self-assessment questionnaire. Twenty three obese subjects (Age: 24-54 years old, 19 men and 4 women, body mass index (BMI) > 26 kg/m2) participated in this study. After the 12-week intervention, the mean reductions in body weight, body mass index and body fat were 4.7 kg, 1.7 kg/m2 and 2.9%, respectively (P < 0.0001). The % change in body weight was significantly associated with the diet score and with the relative training time. The mean reductions in total cholesterol, triglyceride and low density lipoprotein cholesterol were 21 mg/dl (P < 0.002), 34 mg/dl (P < 0.01) and 15.9 mg/dl (P < 0.01), respectively, and the % change in triglyceride was significantly associated with the diet score (P = 0.0056) and tended to correlate with the relative training time (P = 0.0596). Oxygen uptake at AT and at peak exercise were increased from 14.1 +/- 1.6 to 16.0 +/- 3.1 ml/min/kg (P < 0.005) and from 26.3 +/- 4.8 to 28.4 +/- 4.9 ml/min/kg (P < 0.002), respectively. A combination of aerobic exercise and a mild hypocaloric diet significantly contributed not only to weight loss but also to the improvement of dyslipidemia and exercise performance, but either hypocaloric diet or mild exercise independently did less. The diet score and the relative training time were useful for evaluating separately dietary modification and the quantity of exercise.