Download Diet Efficacy in Obesity

Diet Efficacy in Obesity
Gita Majdi
Outline:
• Obesity
• Diet in obesity management
• Types of diet
• Comparisons of diets
• The optimal management of overweight and obesity requires a
combination of diet, exercise, and behavioral modification.
• In addition, some patients eventually require pharmacologic therapy
or bariatric surgery.
Source:What is a reasonable weight loss? Patients' expectations and evaluations of obesity treatment
outcomes. J Consult Clin Psychol. 1997;65(1):79.
GOALS OF WEIGHT LOSS
• An initial weight loss goal of 5 to 7 percent of body weight is realistic
for most individuals.
• The first goal for any overweight individual is to prevent further weight gain
and keep body weight stable (within 5 pounds of its current level).
• A weight loss of more than 5 percent can reduce risk factors for
cardiovascular disease, such as dyslipidemia, hypertension, and
diabetes mellitus .
• An average deficit of 500 kcal/day should result in an initial weight
loss of approximately 0.5 kg/week (1 lb/week).
Source: What is a reasonable weight loss? Patients' expectations and evaluations of obesity treatment outcomes. J Consult Clin Psychol.
1997;65(1):79.
Systematic review of long-term weight loss studies in obese adults: clinical significance and applicability to clinical practice. Douketis JD, Macie C,
Thabane L, Williamson DF, Int J Obes (Lond). 2005;29(10):1153.
• between 1971 and 2004, the average dietary intake of calories in the
United States increased by 22% among women and by 10% among
men, primarily owing to the increased consumption of refined
carbohydrates, starches, and sugar-sweetened beverages.
Source: Lloyd-Jones D, Adams RJ, Brown TM, et al. Heart disease and stroke statistics -- 2010
update: a report from the American Heart Association. Circulation 2010;121:e46-e215[Erratum,
Circulation 2010;121(12):e260.]
• In the Diabetes Prevention Program, a multi-center trial in patients
with impaired glucose tolerance, weight loss of 7 percent reduced
the rate of progression from impaired glucose tolerance to diabetes
by 58 percent.
Changes in Diet and Lifestyle and Long-Term Weight Gain in
Women and Men
Dariush Mozaffarian, M.D., Dr.P.H., Tao Hao, M.P.H., Eric B.
Rimm, Sc.D., Walter C. Willett, M.D., Dr.P.H., and Frank B. Hu,
M.D., Ph.D.
N Engl J Med 2011; 364:2392-2404June 23, 2011DOI:
10.1056/NEJMoa1014296
Study
• Prospective study involving three separate cohorts that included
120,877 U.S.
• women and men who were free of chronic diseases and not obese at
baseline, with follow-up periods from 1986 to 2006, 1991 to 2003,
and 1986 to 2006.
• The relationships between changes in lifestyle factors and weight
change were evaluated at 4-year intervals, with multivariable
adjustments made for age, baseline body-mass index for each period,
and all lifestyle factors simultaneously.
Study population
• Study participants included 50,422 women in the Nurses' Health
Study (NHS), followed for 20 years (1986 to 2006).
• 47,898 women in the Nurses' Health Study II (NHS II), followed
for 12 years (1991 to 2003).
• 22,557 men in the Health Professionals Follow-up Study
(HPFS), followed for 20 years (1986 to 2006).
n a multivariable-adjusted analysis, overall
dietary changes among the 120,877 men and
women in the three cohorts were based on the
sum of changes in the intake of fruits, vegetables,
whole grains, nuts, refined grains, potatoes or
french fries, potato chips, butter, yogurt, sugarsweetened beverages, 100%-fruit juice, sweets
and desserts, processed meats, unprocessed red
meats, trans fat, fried foods consumed at home,
and fried foods consumed away from home.
Panel A shows the relationship between deciles
of dietary change and weight change per 4-year
period in the three cohorts separately and
combined. As compared with persons in the top
decile, persons in the bottom decile had a 5.48-lb
greater weight gain (95% confidence interval [CI],
4.02 to 6.94). Panel B shows the relationship
between the cross-stratified quintiles of changes
in both dietary habits and physical activity with
weight changes per 4-year period for the
combined cohorts. As compared with persons in
the top quintiles of both dietary change and
physical-activity change.
Conclusion:
• Some foods — vegetables, nuts, fruits, and whole grains —
were associated with less weight gain when consumption was
actually increased.
• Their inverse associations with weight gain suggest that the
increase in their consumption reduced the intake of other foods
to a greater (caloric) extent, decreasing the overall amount of
energy consumed.
• Yogurt consumption was also associated with less weight gain
in all three cohorts.
Rate of Weight Loss
• Men lose more weight than women of similar height and weight
when they comply with eating any given diet because men have
more lean body mass, less percent body fat, and therefore
higher energy expenditure.
• Older subjects of either sex have a lower energy expenditure and
therefore lose weight more slowly than younger subjects; metabolic
rate declines by approximately 2 percent per decade (about 100
cal/decade).
• Source:Nutrition and aging: changes in the regulation of energy metabolism with aging. Physiol Rev.
2006;86(2):651.
Types of Diets
• Conventional diets are defined as those below energy requirements but
above 800 kcal/day .
• These diets fall into the following groups:
• Balanced low-calorie diets/portion-controlled diets (weight watchers)
• Low-fat diets (Ornish)
• Low-carbohydrate diets (Atkins)
• Mediterranean diet
Source: Obes Res. 2001 Mar
Balanced low-calorie diets
• Eat foods with adequate nutrients in addition to protein,
carbohydrate, and essential fatty acids.
• Eliminate alcohol, sugar-containing beverages, and most highly
concentrated sweets because they rarely contain adequate
amounts of other nutrients besides energy
Low-fat diets
• In a meta-analysis of trials comparing low-fat diets (typically 20 to 25
percent of energy from fats) with a control group consuming a usual diet or
a medium fat diet (usually 35 to 40 percent of energy), there was greater
weight loss (approximately 3 kg) with low-fat compared with moderate fat
diets.
• one report noted that people who successfully keep their weight
reduced adopt eating a lower fat diet.
•
Source: Ann Behav Med. 2009 Oct;38(2):94-104
• A low-fat dietary pattern with healthy carbohydrates is not associated
with weight gain.
• This was illustrated by the Women's Health Initiative Dietary
Modification Trial of 48,835 postmenopausal women over age 50
years who were randomly assigned to a
1- dietary intervention that included group and individual sessions to
promote a decrease in fat intake and increases in fruit, vegetable, and
grain consumption (healthy carbohydrates), but did not include weight
loss
2- caloric restriction goals, or a control group which received only
dietary educational materials .
• After an average of 7.5 years of follow-up, the following results were
seen:
Conclusion.
• Women in the intervention group lost weight in the first year (mean
of 2.2 kg) and maintained lower weight than the control women at
7.5 years (difference of 1.9 kg at one year, and 0.4 kg at 7.5 years).
• No tendency toward weight gain was seen in the intervention group
overall, or when stratified by age, ethnicity, or body mass index.
• Weight loss was related to the level of fat intake and was greatest in
women who decreased their percentage of energy from fat the most.
Low-fat dietary pattern and weight change over 7 years: the Women's Health Initiative Dietary Modification Trial
.
• DESIGN, SETTING, AND PARTICIPANTS:
• Randomized intervention trial of 48,835 postmenopausal women in the United States who were of diverse backgrounds and
ethnicities and participated in the Women's Health Initiative Dietary Modification Trial; 40% (19,541) were randomized to the
intervention and 60% (29,294) to a control group. Study enrollment was between 1993 and 1998, and this analysis includes a
mean follow-up of 7.5 years (through August 31, 2004).
• INTERVENTIONS:
• The intervention included group and individual sessions to promote a decrease in fat intake and increases in vegetable, fruit, and
grain consumption and did not include weight loss or caloric restriction goals. The control group received diet-related education
materials.
• MAIN OUTCOME MEASURE:
• Change in body weight from baseline to follow-up.
• RESULTS:
• Women in the intervention group lost weight in the first year (mean of 2.2 kg, P<.001) and maintained lower weight than control
women during an average 7.5 years of follow-up (difference, 1.9 kg, P<.001 at 1 year and 0.4 kg, P = .01 at 7.5 years). No tendency
toward weight gain was observed in intervention group women overall or when stratified by age, ethnicity, or body mass index.
Weight loss was greatest among women in either group who decreased their percentage of energy from fat. A similar but lesser
trend was observed with increases in vegetable and fruit servings, and a nonsignificant trend toward weight loss occurred with
increasing intake of fiber.
• CONCLUSION:
• A low-fat eating pattern does not result in weight gain in postmenopausal women.
JAMA. 2006 Jan 4;295(1):39-49
Low carbohydrate
• Low (60 to 130 grams of carbohydrates)
• very low-carbohydrate diets (0 to <60 grams)
• Restriction of carbohydrates leads to glycogen mobilization
and, if carbohydrate intake is less than 50 g/day, ketosis will
develop.
• Rapid weight loss occurs, primarily due to glycogen breakdown
and fluid loss rather than fat loss.
• Low and very low-carbohydrate diets are more effective for shortterm weight loss than low-fat diets, although probably not for longterm weight loss.
High protein diet
• Higher protein diets may improve weight maintenance, as illustrated
by the results of a study of 60 subjects randomly assigned to a low
fat, high protein versus low-fat, high-carbohydrate diet after
completing a four week very low calorie diet .
• Among the subjects who completed the three-month study (n = 48),
the high protein diet group had significantly better weight
maintenance (between group difference of 2.3 kg).
• Source:Int J Obes (Lond). 2009;33(3):296
Side effects?
• High dietary protein intake:
• Increases urinary calcium excretion (with potential risk for bone
loss and calcium stone formation).
• However, two small randomized trials that looked at bone metabolism
found evidence that increased dietary protein may decrease bone
resorption .
• One of the trials found that increased intestinal absorption of
calcium was primarily responsible for the increased urinary excretion
of calcium and that the excreted calcium was not coming from bone
Effect of dietary protein supplements on calcium
excretion in healthy older men and women.
• Thirty-two subjects were randomly assigned to daily high (0.75 g/kg) or low (0.04 g/kg)
protein supplement groups.
• Isocaloric diets were maintained by advising subjects to reduce their intake of
carbohydrates. Selected biochemical measurements were made at baseline and on d 35
and either d 49 or 63.
• Changes in urinary calcium excretion in the two groups did not differ significantly over
the course of the study. The high protein group had significantly higher levels of serum
IGF-I (P = 0.008) and lower levels of urinary N-telopeptide (P = 0.038) over the period of
d 35-49 or 63. We conclude that increasing protein intake from 0.78 to 1.55 g/kg.d with
meat supplements in combination with reducing carbohydrate intake did not alter urine
calcium excretion, but was associated with higher circulating levels of IGF-I, a bone
growth factor, and lowered levels of urinary N-telopeptide, a marker of bone resorption.
• In contrast to the widely held belief that increased protein intake results in calcium
wasting, meat supplements, when exchanged isocalorically for carbohydrates, may have
a favorable impact on the skeleton in healthy older men and women.
• Source: J Clin Endocrinol Metab. 2004;89(3):1169.
The impact of dietary protein on calcium absorption and kinetic
measures of bone turnover in women.
• The study consisted of 2 wk of a well-balanced diet followed by 10 d of an
experimental diet containing either moderate (1.0 g/kg) or high (2.1 g/kg)
protein.
• Thirteen healthy women received both levels of protein in random order.
• Intestinal calcium absorption increased during the high-protein diet in
comparison with the moderate (26.2 +/- 1.9% vs. 18.5 +/- 1.6%, P<0.0001, mean
+/- sem) as did urinary calcium (5.23 +/- 0.37 vs. 3.57 +/- 0.35 mmol/d, P<0.0001,
mean +/- sem).
• The high-protein diet caused a significant reduction in the fraction of urinary
calcium of bone origin and a nonsignificant trend toward a reduction in the rate
of bone turnover.
• There were no protein-induced effects on net bone balance.
• These data directly demonstrate that, at least in the short term, high-protein
diets are not detrimental to bone.
• Source:J Clin Endocrinol Metab. 2005;90(1):26
Mediterranean diet
Include a high level of monounsaturated fat
relative to saturated;
Moderate consumption of alcohol, mainly as
wine;
High consumption of vegetables, fruits,
legumes, and grains;
Moderate consumption of milk and dairy
products, mostly in the form of cheese;
Relatively low intake of meat and meat
products.
Mediterranean diet
• This meta-analysis shows, in an overall analysis comprising more than
1.5 million healthy subjects and 40 000 fatal and non-fatal events,
that greater adherence to a Mediterranean diet is significantly
associated with a reduced risk of overall mortality, cardiovascular
mortality, cancer incidence and mortality, and incidence of
Parkinson’s disease and Alzheimer’s disease.
• Source BMJ. 2008; 337: a1344.:
Very low-calorie diets
• Diets with energy levels between 200 and 800 kcal/day are called
"very low-calorie diets," while those below 200 kcal/day can be
termed starvation diets.
• Starvation is the ultimate very low-calorie diet and results in the most
rapid weight loss. Starvation diets are now rarely used for treatment
of obesity.
• Very low-calorie diets have not been shown to be superior to
conventional diets for long-term weight loss.
• In a meta-analysis of six trials comparing very low-calorie diets
with conventional low-calorie diets, short-term weight loss was
greater with very low-calorie diets (16.1 versus 9.7 versus
percent of initial weight), but there was no difference in longterm weight loss (6.3 versus 5.0 percent).
• Source:Obesity . 2006 Aug;14(8):1283-93
Comparison trials
• The impact of specific dietary composition on weight change remains
uncertain.
• When energy from dietary carbohydrates decreases, energy from fat
sources tends to increase.
• When energy from dietary fats decreases, energy from carbohydrate
sources tends to increase.
• The debate has mainly centered on whether low-fat or low-carbohydrate
diets can better induce weight loss and sustain it over the long-term.
• Some of these initial comparison trials of different dietary regimens had
important limitations . These included high dropout rates (21 to 48
percent), suboptimal dietary compliance, and limited long-term follow-up.
Weight loss diets
• Initial trials evaluating the effect of type of diet (predominantly lowcarbohydrate versus low-fat) on weight loss and other outcomes
showed that weight loss at six months was approximately 4 kg greater
in the very low-carbohydrate group than in the low-fat group.
• Trials lasting for one year, however, did not find a significant
difference in weight loss.
• OBJECTIVE: To compare the effects of a low-carbohydrate, ketogenic diet
program with those of a low-fat, low-cholesterol, reduced-calorie diet
• 120 overweight, hyperlipidemic volunteers from the community.
• Low-carbohydrate diet (initially, <20 g of carbohydrate daily) plus
nutritional supplementation, exercise recommendation, and group
meetings
• low-fat diet (<30% energy from fat, <300 mg of cholesterol daily, and
deficit of 500 to 1000 kcal/d) plus exercise recommendation and group
meetings.
• CONCLUSIONS:
• Compared with a low-fat diet, a low-carbohydrate diet program had better
participant retention and greater weight loss. During active weight loss,
serum triglyceride levels decreased more and high-density lipoprotein
cholesterol level increased more with the low-carbohydrate diet than with
the low-fat diet.
• Source:Ann Intern Med. 2004 May 18;140(10):769-7
Longer Follow up
• Meta-analyses of trials comparing low-fat and low-carbohydrate diets
found that the difference in weight loss at six months (weighted mean
difference 3 to 4 kg), favoring the low carbohydrate over low fat diet,
was not sustained at 12 to 24 months (weighted mean difference 1
kg)
• In one study, this convergence was mainly due to regain of weight in
the low-carbohydrate group .
• In another, the convergence was due to ongoing weight loss in the
low-fat group.
• Source:Ann Intern Med. 2004;140(10):778
Comparison of mean weight loss in kg
between subjects on a conventional diet (red
circles) and a low-carbohydrate diet (blue
squares). The difference in weight loss was
no longer significant at one year.
Data from: Stern L, Iqbal N, Seshadri P, et al.
The effects of low-carbohydrate versus
conventional weight loss diets in severely
obese adults: one-year follow-up of a
randomized trial. Ann Intern Med 2004;
140:778.
Weight Loss with a Low-Carbohydrate, Mediterranean, or LowFat Diet
Iris Shai, R.D., Ph.D., Dan Schwarzfuchs, M.D., Yaakov Henkin,
M.D., Danit R. Shahar, R.D., Ph.D., Shula Witkow, R.D., M.P.H.,
Ilana Greenberg, R.D., M.P.H., Rachel Golan, R.D., M.P.H., Drora
Fraser, Ph.D., Arkady Bolotin, Ph.D., Hilel Vardi, M.Sc., Osnat
Tangi-Rozental, B.A., Rachel Zuk-Ramot, R.N., Benjamin Sarusi,
M.Sc., Dov Brickner, M.D., Ziva Schwartz, M.D., Einat Sheiner,
M.D., Rachel Marko, M.Sc., Esther Katorza, M.Sc., Joachim
Thiery, M.D., Georg Martin Fiedler, M.D., Matthias Blüher, M.D.,
Michael Stumvoll, M.D., and Meir J. Stampfer, M.D., Dr.P.H. for
the Dietary Intervention Randomized Controlled Trial (DIRECT)
Group
N Engl J Med 2008; 359:229-241July 17, 2008
322 moderately obese subjects (86 percent men) were randomly assigned
to a low-fat (restricted calorie), Mediterranean (moderate-fat, restricted
calorie, rich in vegetables, low in red meat), or low-carbohydrate (nonrestricted-calorie) diet for two years.
Adherence rates were higher than those reported in previous trials (95.4
and 84.6 percent at one and two years, respectively). Weight loss was
greater with the Mediterranean and low-carbohydrate diets than the lowfat diet (mean weight loss 4.4, 4.7, and 2.9 kg, respectively).
The most favorable effect on lipids (increased high-density lipoprotein
[HDL] and decreased triglycerides and ratio of total cholesterol to HDL)
was seen in the low-carbohydrate group.
Among subjects with type 2 diabetes, the greatest improvement in
glycemic control occurred with the Mediterranean diet.
Among all groups, weight loss was greater for those who completed the
two year study than for those who withdrew.
Vertical bars indicate standard errors. To
statistically evaluate the changes in weight
measurements over time, generalized
estimating equations were used, with the
low-fat group as the reference group. The
explanatory variables were age, sex, time
point, and diet group.
Panel A shows the results for serum highdensity lipoprotein (HDL) cholesterol, Panel B
for serum triglycerides, Panel C for serum lowdensity lipoprotein (LDL) cholesterol, and Panel
D for the ratio of total cholesterol to HDL
cholesterol. Vertical bars indicate standard
deviations. To statistically evaluate the changes
in weight measurements over time, generalized
estimating equations were used, with the lowfat group as the reference group. The
explanatory variables were age, sex, time point,
and diet group. Results are presented for the
82% of the study population (263 participants)
with blood-sample data at all time points (90 in
the low-fat group, 92 in the Mediterranean-diet
group, and 81 in the low-carbohydrate group).
The P values for the comparison between the
low-fat group and the Mediterranean-diet group
are 0.94 for HDL cholesterol, 0.21 for
triglycerides, 0.41 for LDL cholesterol, and 0.23
for the ratio of total cholesterol to HDL
cholesterol. The P values for the comparison
between the low-fat group and the lowcarbohydrate group are 0.01 for HDL
cholesterol, 0.03 for triglycerides, 0.94 for LDL
cholesterol, and 0.01 for the ratio of total
cholesterol to HDL cholesterol. To convert values
for
• In this 2-year dietary-intervention study:
• Mediterranean and low-carbohydrate diets are effective alternatives
to the low-fat diet for weight loss and appear to be just as safe as the
low-fat diet.
• The similar caloric deficit achieved in all diet groups suggests that a
low-carbohydrate, non–restricted-calorie diet may be optimal for
those who will not follow a restricted-calorie dietary regimen.
• The increasing improvement in levels of some biomarkers over time
up to the 24-month point, despite the achievement of maximum
weight loss by 6 months, suggests that a diet with a healthful
composition has benefits beyond weight reduction.
Results:
• Two phases of weight change:
• initial weight loss and weight maintenance.
• The maximum weight reduction was achieved during the first 6
months.
• this period was followed by the maintenance phase of partial
rebound and a plateau.
• Among all diet groups, weight loss was greater for those who
completed the 24-month study than for those who did not.
• Even moderate weight loss has health benefits
• Behavioral approaches yield weight losses similar to those obtained
with pharmacotherapy.
• They observed two phases of weight change: initial weight loss and
weight maintenance.
• The maximum weight reduction was achieved during the first 6
months; this period was followed by the maintenance phase of partial
rebound and a plateau.
• Among all diet groups, weight loss was greater for those who
completed the 24-month study than for those who did not. Even
moderate weight loss has health benefits, and our findings suggest
benefits of behavioral approaches that yield weight losses similar to
those obtained with pharmacotherapy.
Comparison of Weight-Loss Diets with
Different Compositions of Fat, Protein,
and Carbohydrates
Frank M. Sacks, M.D., George A. Bray, M.D., Vincent J.
Carey, Ph.D., Steven R. Smith, M.D., Donna H. Ryan,
M.D., Stephen D. Anton, Ph.D., Katherine McManus,
M.S., R.D., Catherine M. Champagne, Ph.D., Louise M.
Bishop, M.S., R.D., Nancy Laranjo, B.A., Meryl S. Leboff,
M.D., Jennifer C. Rood, Ph.D., Lilian de Jonge, Ph.D.,
Frank L. Greenway, M.D., Catherine M. Loria, Ph.D., Eva
Obarzanek, Ph.D., and Donald A. Williamson, Ph.D.
N Engl J Med 2009; 360:859-873February 26, 2009DOI:
10.1056/NEJMoa0804748
• Comparison of the Atkins, Zone, Ornish, and LEARN Diets for Change
in Weight and Related Risk Factors Among Overweight
Premenopausal Women
• The A TO Z Weight Loss Study: A Randomized Trial
• Christopher D. Gardner, PhD; Alexandre Kiazand, MD; Sofiya
Alhassan, PhD; Soowon Kim, PhD; Randall S. Stafford, MD, PhD;
Raymond R. Balise, PhD; Helena C. Kraemer, PhD; Abby C. King, PhD
• Stanford Prevention Research Center and the Department of
Medicine, Stanford University Medical School, Stanford, Calif.
• Source: Jama 2007
• Atkins (very low in carbohydrate )
• Zone (low in carbohydrate),
• LEARN (Lifestyle, Exercise, Attitudes, Relationships, and Nutrition;
low in fat, high in carbohydrate, based on national guidelines)
• Ornish (very high in carbohydrate).
Atkins (very low in carbohydrate )
Zone (low in carbohydrate),
LEARN (Lifestyle, Exercise, Attitudes,
Relationships, and Nutrition; low in fat, high
in carbohydrate, based on national
guidelines)
Ornish (very high in carbohydrate).
The primary study objective was to examine
the effects of diets and gradations of
carbohydrate intake on weight loss and
related metabolic variables in overweight
and obese premenopausal women.
premenopausal overweight and obese
women assigned to follow the Atkins diet,
which had the lowest carbohydrate intake,
lost more weight and experienced more
favorable overall metabolic effects at 12
months than women assigned to follow the
Zone, Ornish, or LEARN diets.
Weight Loss at 2 Years
According to Adherence
to Dietary Fat and
Protein Goals
Intake was determined from three 24-hour diet
recalls. Quintiles of fat and protein intakes are
shown for the combined high-fat groups (Panel
A), low-fat groups (Panel B), high-protein groups
(Panel C), and average-protein groups (Panel D);
there were 45 to 51 participants per quintile.
Rates of attendance at group sessions (percent
of total sessions attended over the 2-year
period) are shown for the quintiles of fat and
protein intake. I bars indicate 95% confidence
intervals. P values for a trend in weight loss
across quintiles are as follows: P<0.001 for fat
intake in low-fat groups, P<0.001 for protein
intake in high-protein groups, P=0.36 for fat
intake in high-fat groups, and P=0.83 for protein
intake in average-protein groups. The results
were similar when determined within each of
the four diet groups (data not shown).
• Results :
• At 6 months, participants assigned to each diet had lost an average of 6 kg,
which represented 7% of their initial weight; they began to regain weight
after 12 months.
• By 2 years, weight loss remained similar .
• Among the 80% of participants who completed the trial, the average
weight loss was 4 kg; 14 to 15% of the participants had a reduction of at
least 10% of their initial body weight.
• Satiety, hunger, satisfaction with the diet, and attendance at group
sessions were similar for all diets; attendance was strongly associated with
weight loss (0.2 kg per session attended).
• The diets improved lipid-related risk factors and fasting insulin levels.
• Conclusion: Reduced-calorie diets result in clinically meaningful weight loss
regardless of which macronutrients they emphasize.
Diets with High or Low Protein Content and Glycemic Index for
Weight-Loss Maintenance
Thomas Meinert Larsen, Ph.D., Stine-Mathilde Dalskov, M.Sc.,
Marleen van Baak, Ph.D., Susan A. Jebb, Ph.D., Angeliki
Papadaki, Ph.D., Andreas F.H. Pfeiffer, M.D., J. Alfredo Martinez,
Ph.D., Teodora Handjieva-Darlenska, M.D., Ph.D., Marie
Kunešová, M.D., Ph.D., Mats Pihlsgård, Ph.D., Steen Stender,
M.D., Ph.D., Claus Holst, Ph.D., Wim H.M. Saris, M.D., Ph.D.,
and Arne Astrup, M.D., Dr.Med.Sc. for the Diet, Obesity, and
Genes (Diogenes) Project
N Engl J Med 2010; 363:2102-2113November 25, 2010
Study:
• A total of 1209 adults were screened (mean age, 41 years; body-mass
index 34), of whom 938 entered the low-calorie-diet phase of the
study. A total of 773 participants who completed that phase were
randomly assigned to one of the five maintenance diets; 548
completed the intervention (71%).
• The mean initial weight loss with the low-calorie diet was 11.0 kg.
Results & Conclusion
• Fewer participants in the high-protein and the low-glycemic-index
groups than in the low-protein–high-glycemic-index group dropped
out of the study (26.4% and 25.6%, respectively, vs. 37.4%; P=0.02
and P=0.01 for the respective comparison).
• In this large European study, a modest increase in protein content and
a modest reduction in the glycemic index led to an improvement in
study completion and maintenance of weight loss.
Summary:
• Thus, any diet that is adhered to will produce modest weight loss, but
adherence rates are low with most diets.
• Although a low-carbohydrate diet may be associated with greater
short-term weight loss, superior weight loss in the long-term has not
been established.
• A principal determinant of weight loss appears to be the degree of
adherence to the diet, irrespective of the particular macronutrient
composition
• Behavioral modification to improve dietary compliance with any type
of diet may have the greatest impact on long-term weight loss