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Similar weight loss with low-energy food
combining or balanced diets
A Golay
1
*, A-F Allaz
2,3
, J Ybarra
4
, P Bianchi
1
, S Saraiva
1
, N Mensi
1
, R Gomis
4
and N de Tonnac
3
1
Division of Therapeutic Patient Education for Chronic Diseases, University Hospital Geneva, Geneva, Switzerland;
2
Department of
Internal Medicine, University Hospital Geneva, Geneva, Switzerland;
3
Department of Psychiatry, University Hospital Geneva, Geneva,
Switzerland; and
4
Servei d'Endocrinologia I Nutricio, Hospital Clinic, Barcelona, Spain
OBJECTIVE: The goal of this study was to evaluate the effect of two diets (`food combining' or dissociated
vs
balanced) on body weight and metabolic parameters during a 6-week period in an in-hospital setting.
SUBJECTS AND DESIGN: 54 obese patients were randomly assigned to receive diets containing 4.5 MJ=day (1100
kcal=day) composed of either 25% protein, 47% carbohydrates and 25% lipids (dissociated diet) or 25% protein, 42%
carbohydrates and 31% lipids (balanced diet). Consequently, the two diets were equally low in energy and substrate
content (protein, fat and carbohydrate) but widely differed in substrate distribution throughout the day.
RESULTS: There was no signi®cant difference in the amount of weight loss in response to dissociated (6.2 0.6 kg) or
balanced (7.5 0.4 kg) diets. Furthermore, signi®cant decreases in total body fat and waist-to-hip circumference ratio
were seen in both groups, and the magnitude of the changes did not vary as a function of the diet composition.
Fasting plasma glucose, insulin, total cholesterol and triacylglycerol concentrations decreased signi®cantly and
similarly in patients receiving both diets. Both systolic and diastolic blood pressure values decreased signi®cantly
in patients eating balanced diets. The results of this study show that both diets achieved similar weight loss. Total fat
weight loss was higher in balanced diets, although differences did not reach statistical signi®cance. Total lean body
mass was identically spared in both groups.
CONCLUSION: In summary at identical energy intake and similar substrate composition, the dissociated (or `food
combining') diet did not bring any additional loss in weight and body fat.
I nternational Journal of O besity (2000) 24, 492±496
Keywords: weight loss; dissociated diet; balanced diet
Introduction
Obesity is nowadays commonly accepted as a chronic
disease associated with known co-morbid conditions
such as type 2 diabetes mellitus,
1±3
hypertension,
coronary artery disease, hypercholesterolaemia,
arthrosis, gout and cancer,
4±6
as well as a reduction
in life expectancy. During the last decade a large
amount of information regarding its pathophysiology,
and more speci®cally the adipocyte's signalling
mechanisms, has emerged. Despite several missing
links in the aetiology of this complex and heteroge-
neous disease, most authorities agree upon a disequi-
librium between energy intake and expenditure being
a key factor in the development of obesity. Thus, total
energy intake plays a pivotal role in the development
and maintenance of obesity.
Patient education and dietetic counselling are man-
datory as the ®rst steps in the therapeutic approach to
obesity. Concerning the in¯uence of qualitative diet
composition on weight loss, several authors
7±10
agree
that the total energy intake, and not its composition,
determines the ®nal weight loss. Nevertheless, when it
comes to long-term follow-up, mixed, varied and
individually tailored diets achieve better compli-
ance.
11,12
Once total energy intake has been ade-
quately reduced and tailored to the patient's
individual needs, compliance becomes an issue.
Long-term outpatient dietary studies tend to show a
decrease in compliance with time.
13
The latter is
dif®cult to assess on an ambulatory basis where the
main source of information relies on dietary diaries.
14
Theoretically, it should be easier to monitor and
therefore improve patient dietary adherence in an in-
hospital setting. Unfortunately these kind of studies
require a multi-disciplinary approach, are time-con-
suming and are rarely attempted.
All sorts of different diets have been popularized by
the media in recent years.
15 ± 17
Among them, disso-
ciated diets, commonly known as food combining
diets, have lately gained popularity and have gathered
a full array of false beliefs concerning their potential
bene®ts. Their main principle consists in spreading the
intake of substrates (carbohydrate, fats and proteins)
throughout daytime. Montignac
18
states that carbohy-
drates and lipids should not be ingested simulta-
neously during a meal since the former, acting as a
potent insulin secretagogue, would favour an increase
in fat cell stores (i.e. insulin's antilipolytic and lipo-
genic effect). Interestingly enough this statement
relies purely on a theoretical basis and is lacking
*Correspondence: A Golay, Division of Therapeutic Education
for Chronic Diseases, University Hospital Geneva, 24 rue
Micheli-du Crest, 1211-Geneva-14, Switzerland.
E-mail: Alain.Golay@hcuge.ch
Received 4 May 1999; revised 17 September 1999; accepted
26 November 1999
International Journal of Obesity (2000) 24, 492±496
ß 2000 Macmillan Publishers Ltd All rights reserved 0307±0565/00 $15.00
www.nature.com/ijo
scienti®c proof. On the contrary, Bobbioni-Harsch
et al
19
have recently shown that energy expenditure
and substrates oxidative patterns are identical after
glucose, fat or mixed loads in normal weight subjects
on a short-term basis (8 h).
The aim of our study is to compare the medium-
term (6 weeks) effects of a low-calorie (1000 kcal=
day) dissociated vs balanced (1000 kcal=day) diet in
an in-hospital setting.
Material and methods
Fifty-four adult obese patients were studied before,
during and after a 6-week period of hospitalization.
These subjects had been referred to the Obesity Out-
patient Clinic of the Department of Medicine at
Geneva University Hospital for dietary treatment of
their obesity.
During the ®rst visit, it was decided on the basis of
a failure to lose weight in response to ambulatory
treatment that these individuals would bene®t if they
were hospitalized for the ®rst 6 weeks of treatment.
Criteria for admission included a body mass index
> 30 kg=m
2
strong personal motivation, and the
ability to participate in the requisite amount of phy-
sical activity. Patients with obesity secondary to
endocrine disease, as well as those with psychiatric
diagnoses were excluded from the study. The protocol
was submitted to and accepted by the ethical commit-
tee of the Department of Medicine at Geneva Uni-
versity Hospital. In addition to a low calorie diet,
subjects participated in a structured, multidisciplinary
program that included physical activity, nutritional
education and standard behavioural techniques. Exer-
cise consisted of 1 h of aerobic exercise training per
day and 1 h of exercises in a swimming pool per day.
Nutritional education was provided by a registered
dietitian twice a week (once in a group session
and once individually). The cognitive ± behavioral
approach consisted of six sessions, during which
issues of self-control, cognitive restructuring, reinfor-
cement, and relapse prevention were addressed.
On admission to the hospital, patients were ran-
domly assigned to two groups whose baseline char-
acteristics are listed in Table 1. After baseline
metabolic data were acquired, the patients were
assigned to receive one of the two experimental
diets whose composition is listed in Table 2. Both
diets consisted of natural foods. Recipes and menus
of various food items were standardized. A 7 day
rotational menu was employed. The menus provided
similar protein composition but offered diverse foods.
Itemized composition of meals from one day of the
rotation menu for the balanced and dissociated diets
are given in Table 3. Protein intake was ®xed to be at
least 25% of the total daily energy intake (1.2 g of
protein=kg of ideal body weight)
7,20
in order to avoid
Table 1 Physical characteristics of the subjects
B a lanced, D issocia ted ,
n 21 F , 7 M n 20 F, 6 M
Age (y) 43.1 2.9 44.0 3.5
Height (cm) 165.2 1.5 165.4 2.7
Weight (kg) 105.5 3.6 104.5 2.8
BMI (kg=m
2
) 38.5 0.9 38.8 1.8
Waist circumference (cm) 114.8 2.3 115.7 4.0
Hip circumference (cm) 122.5 1.9 120.3 2.9
Waist-to-hip ratio 0.94 0.02 0.96 0.03
Systolic blood pressure (mmHg) 135.0 3.5 130.0 4.1
Diastolic blood pressure (mmHg) 85.8 2.1 85.6 5.0
Table 2 Composition of the diets
a
D iet B a lanced Di ssocia ted
Energy (MJ=day) 4.6 0.08 4.5 0.04
Carbohydrates (%) (g=day) 114 4 123 3
42 147 1
Lipids (%) (g=day) 38 129 2
31 125 2
Proteins (%) (g=day) 72 171 2
27 0.4 27 0.9
Average protein losses
between weeks (0 and 6) (g=day)
71 371 4
a
X s.e.m.
Table 3 Itemized composition of diets
Food items Weight (g)
B a lanced diet
Breakfast:
low-fat skimmed milk (0%) 150
whole wheat bread 50
butter or margarine 5
Lunch:
low-fat meat or ®sh 100
vegetable 150
rice, pasta, or cereals 60
fruit 100
oil 5
Snack:
low-fat arti®cially sweetened yogurt 180
Dinner:
low-fat meat or eggs 100
vegetable 150
rice, pasta, or cereals 60
oil 5
Snack:
Low-fat fresh cheese (20% fat) 50
fruit 100
Dissociated diet
Breakfast:
low-fat skimmed milk (0%) 150
wholewheat bread 50
arti®cially sweetened marmalade 25
Lunch:
low-fat meat or ®sh 100
vegetable 150
low-fat fresh cheese (25%) 25
oil 10
Snack:
low-fat arti®cially sweetened yogurt 180
Dinner:
low-fat skimmed cheese (0%) 100
vegetable 150
rice, pasta, or cereals 100
Snack:
fruit 200
Similar weight loss with food combining diets
A Golay
et al
493
International Journal of Obesity
muscular wasting. Group 1 (n 28, 21 F=7M)
received a balanced diet while group 2 (n 26, 20
F=6 M) received a dissociated diet. Both experimental
diets had identical energy content (4.5 MJ=day, 1100
kcal=day). The balanced diet's composition was 42%
carbohydrates and 31% lipids. The dissociated diet's
composition was 47% carbohydrates and 25% lipids.
Both diets contained similar amounts of saturated fat
(14 g=day) and cholesterol (230 mg=day). Daily
energy intake was distributed between breakfast
(22%), lunch (33%), dinner (33%) and bedtime
snack (12%). Energy intake was carefully measured
for each patient. All subjects were instructed to eat all
foods and a dietitian was present during each meal to
improve compliance and education. To verify com-
pliance with the diet and mainly for education pur-
pose, patients completed a one day food record once a
week during the 6 weeks of the study. These food
records took the quality and the quantity of the
consumed food into account. The software
PRODI3 was used to calculate meal plans and
food records.
21
The food composition tables used
were from Souci et al
22
and Renaud and Attil.
23
The balanced diet associated the three substrates
during each meal, while dissociated diets did not
allow simultaneous consumption of lipids and carbo-
hydrates. Blood was drawn after a 14 h overnight fast
before and after 2, 4 and 6 weeks of both balanced and
dissociated diets for measurements of plasma glu-
cose,
24
plasma immunoreactive insulin,
25
total chol-
esterol,
26
high-density-lipoprotein (HDL)-cholesterol,
and triacylglycerol concentrations.
27
Nitrogen balance
was measured to compare the protein-sparing effect of
both diets. Urinary nitrogen was measured by the
Kjeldahl method.
28
Twenty-four-hour urine samples
were collected every week and average urinary loss
was computed on the basis of these six collections.
Integumental and stool losses were estimated on the
basis of previously reported studies; 5 and 10 mg=kg
body weight, respectively.
29
Daily nitrogen balance
was calculated by subtracting total output (urine,
stool=and integumental losses) from dietary input.
Body fat composition and percentage of adiposity
were determined by bioelectrical impedance analy-
sis.
30
Data are expressed as means statistically sig-
ni®cant (95% con®dence) s.e.m.s and were analysed
with the Statview4 software package. To evaluate the
differences the two groups of obese patients, before
and after weight loss, data were analysed by two-way
analysis of variance, with the multiple-comparison
approach of Scheffe.
Results
As depicted in Table 2, daily protein intake and
average protein losses were very similar in both
groups. Being equally low in energy, both diets
were similarly catabolic. Values for age, systolic and
diastolic blood pressure values, total body weight,
BMI, waist and hip circumferences, and waist-to-hip
ratio before the diets are given in Table 4. These
values were perfectly comparable between the two
groups at baseline. Total body weight, body mass
index, waist and hip circumferences (as well as their
ratio) decreased signi®cantly in both groups and the
magnitude of the changes did not vary as a function of
the type of diet; nevertheless the group receiving the
balanced diet showed a tendency to lose weight more
than the group on the dissociated diet (7.5 0.4 kg vs
6.2 0.6 kg, P NS).
Total weight loss occurred in a progressive and
similar way in both groups (Figure 1a). At the end of
the study both groups achieved similar signi®cant fat
body weight losses (Figure 1b).
Both systolic and diastolic blood pressure values
decreased signi®cantly in the group receiving
balanced diet, but not in the other group. However,
there were no differences between two groups.
Table 5 lists values for fasting plasma glucose,
insulin, cholesterol, HDL-cholesterol and triacyl-
glycerol concentrations before and after 6 weeks of
dietary intervention. At baseline there were no sig-
ni®cant differences in either group. In both groups
plasma glucose, cholesterol, HDL-cholesterol and
triacylglycerol concentrations decreased signi®cantly.
Similarly, insulin concentrations decreased in both
groups at the end of the study.
Table 4 Body composition before and after weight loss
a
B a lanced Di ssocia ted
Before After Before After
Weight (kg) 105.5 3.6 98.1 3.3*** 104.5 2.8 96.5 2.2***
BMI (kg=m
2
) 38.5 0.9 35.8 0.9*** 38.8 1.8 35.2 1.3***
Waist circumference (cm) 114.8 2.3 105.9 2.3*** 115.7 4.0 108.0 3.9***
Hip circumference (cm) 122.5 1.9 114.1 1.8*** 120.3 2.9 114.8 2.2*
Waist=hip ratio 0.94 0.02 0.92 0.02* 0.96 0.03 0.94 0.03
Systolic blood pressure (mmHg) 135 3.5 124.3 1.8** 130.0 4.1 125.0 3.8
Diastolic blood pressure (mmHg) 85.8 2.1 81.0 2.3* 85.6 5.0 75.0 3.3
a
X s.e.m.
*P < 0.05; **P < 0.01; ***P< 0.001.
Similar weight loss with food combining diets
A Golay
et al
494
International Journal of Obesity
Discussion
In this study we evaluated the effects of two low-
energy diets (balanced and dissociated) on both
weight loss (total and fat body weight) and various
metabolic parameters. The amount of weight loss was
similar in response to the two diets (which had similar
energy and macronutrients contents (Table 2)) and
was apparently independent of the substrate distribu-
tion within meals, being principally related to total
energy intake, in accordance with previous works
from our group and others.
7,8
The theoretical energy
expenditure with each diet was calculated using the
Harris ± Benedict formula. According to the latter, the
expected fat loss would be 4.5 kg in 6 weeks. The
theoretical fat loss was then compared to the fat loss
assessed by electrical bio-impedance. Therefore, diet-
ary compliance was maximal in the group receiving
the balanced diet (100%), while it was estimated to be
84% in the group receiving the dissociated diet. These
differences in calculated compliance may account for
the differences in observed weight loss. The small, not
signi®cant, difference in body fat loss may also be
due to inaccurate determination by bioelectrical
impedance.
Systolic and diastolic blood pressure values fell
signi®cantly in the group receiving balanced diet,
but there were no differences between the groups in
the change in blood pressure. Interestingly dietary salt
content was similar in both diets and none of the
patients in either group were on anti-hypertensive
medications. In opposition to popular beliefs, varia-
tions in the daily distribution of substrates did not add
any supplemental metabolic bene®t. More speci®-
cally, both diets allowed a signi®cant improvement
in fasting plasma glucose, cholesterol and triacylgly-
cerol values. At the end of the study there were no
signi®cant differences in plasma glucose, insulin,
triacylglycerol or HDL-cholesterol between the two
groups. In conclusion, our results substantiate the lack
of bene®t of dissociated (food combining) vs balanced
diets in terms of weight loss and further support that it
is energy intake, not energy composition or distribu-
tion throughout daytime, that determines weight loss
in response to low-energy diets.
Acknowledgements
We are grateful to the members of the Dietary staff of
the Department of Medicine for their assistance, in
particular to P Rigoli, C Bussien and J Duffey.
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