Original Article

International Journal of Obesity (2006) 30, 552–560. doi:10.1038/sj.ijo.0803186; published online 6 December 2005

Randomized, multi-center trial of two hypo-energetic diets in obese subjects: high- versus low-fat content

M Petersen1,11, M A Taylor2,11, W H M Saris3, C Verdich4, S Toubro1, I Macdonald2, S Rössner5, V Stich6, B Guy-Grand7, D Langin8, J A Martinez9, O Pedersen10, C Holst4, T I A Sørensen1, A Astrup1 and and The Nugenob Consortium12,13

  1. 1Institute of Human Nutrition, The Royal Veterinary and Agricultural University, Copenhagen, Denmark
  2. 2School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
  3. 3Department of Human Biology, Nutrition and Toxicology Research Centre NUTRIM, Maastricht University, Maastricht, The Netherlands
  4. 4Institute of Preventive Medicine, Danish Epidemiology Science Centre, Copenhagen University Hospital, Copenhagen, Denmark
  5. 5The Obesity Unit, Department of Medicine, Karolinska Institute, Huddinge University Hospital, Sweden
  6. 6Department of Sports Medicine, Centre of Preventive Medicine, Third Faculty of Medicine, Charles University, Praha, Czech Republic
  7. 7Department of Nutrition, Hôtel-Dieu, Paris, France
  8. 8Obesity Research Unit Inserm U586, Louis Bugnard Institute and Clinical Investigation Centre, Toulouse University Hospitals, Paul Sabatier University, Toulouse, France
  9. 9Department Physiology and Nutrition, University of Navarra, Pamplona, Spain
  10. 10Steno Diabetes Centre, Gentofte, Denmark

Correspondence: Professor A Astrup, Department of Human Nutrition, Centre for Advanced Food Studies, Rolighedsvej 30, 1958 Frederiksberg C, Denmark. E-mail: ast@kvl.dk

11These authors have contributed equally to this work.

12Current address: The NUGENOB Co-ordination Centre, Institute of Preventive Medicine, Oester Soegade 18.1, DK-1357 Copenhagen K, Denmark. E-mail: tias@ipm.hosp.dk or cv@ipm.hosp.dk

13NUGENOB is the acronym of the project 'Nutrient-Gene interactions in human obesity – implications for dietary guidelines' supported by the European Community (Contract no. QLK1-CT-2000-00618), see the web-site www.nugenob.org

Received 7 January 2005; Revised 1 May 2005; Accepted 29 May 2005; Published online 6 December 2005.

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Abstract

Objective:

 

To investigate whether a hypo-energetic low-fat diet is superior to a hypo-energetic high-fat diet for the treatment of obesity.

Design:

 

Open-label, 10-week dietary intervention comparing two hypo-energetic (-600 kcal/day) diets with a fat energy percent of 20–25 or 40–45.

Subjects:

 

Obese (BMI greater than or equal to30 kg/m2) adult subjects (n=771), from eight European centers.

Measurements:

 

Body weight loss, dropout rates, proportion of subjects who lost more than 10% of initial body weight, blood lipid profile, insulin and glucose.

Results:

 

The dietary fat energy percent was 25% in the low-fat group and 40% in the high-fat group (mean difference: 16 (95% confidence interval (CI) 15–17)%). Average weight loss was 6.9 kg in the low-fat group and 6.6 kg in the high-fat group (mean difference: 0.3 (95% CI -0.2 to 0.8) kg). Dropout was 13.6% (n=53) in the low-fat group and 18.3% (n=70) in the high-fat group (P=0.001). Among completers, more subjects lost >10% in the low-fat group than in the high-fat group ((20.8%, n=70) versus (14.7%, n=46), P=0.02). Fasting plasma total, low-density lipoprotein- and high-density lipoprotein-cholesterol decreased in both groups, but more so in the low-fat group than in the high-fat group. Fasting plasma insulin and glucose were lowered equally by both diets.

Conclusions:

 

The low-fat diet produced similar mean weight loss as the high-fat diet, but resulted in more subjects losing >10% of initial body weight and fewer dropouts. Both diets produced favorable changes in fasting blood lipids, insulin and glucose.

Keywords:

blood lipids, lipoprotein-cholesterol, drop-out rate, low-carbohydrate diet

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Introduction

The rapidly increasing prevalence of obesity is a major, global health problem because of the increased risk of serious complications such as cardiovascular disease, type 2 diabetes and some cancers.1 Even a minor weight loss of 4–6% in obese individuals with impaired glucose tolerance is associated with a reduction of the risk of type 2 diabetes by 58% within 3–5 years.2, 3

Successful weight loss depends upon achieving negative energy balance, and the scientific debate regarding the optimal macronutrient composition for the dietary treatment of obesity requires a better evidence-based fundament. Meta-analyses of intervention trials have demonstrated that ad libitum low-fat diets produce 3–4 kg weight loss over 3–6 months,4 and there is some evidence to suggest that weight maintenance is easier to achieve by a fat-reduced diet than with a higher fat diet.5 While there is little evidence to support any important difference between low-fat diets with complex and simple carbohydrates,6 higher protein levels might improve weight loss.7 However, very few randomized trials have been conducted, which combine energy restriction and compare different levels of energy from fat and carbohydrate. These studies have included only small numbers of obese subjects and have therefore limited statistical power to detect clinically relevant differences in weight loss and body composition.8, 9

Dietary composition also affects risk factors for cardiovascular disease and type 2 diabetes independently of weight loss. Increasing the percentage of total energy from carbohydrate while decreasing the percentage of energy from fat may lower fasting plasma total and low-density lipoprotein (LDL)-cholesterol and also high-density lipoprotein (HDL)-cholesterol concentrations, and increase, at least initially, fasting plasma triacylglycerol concentration.10, 11 The same changes in the diet induce a lowering of fasting plasma insulin concentrations, reflecting an increase in whole-body insulin sensitivity.12 However, it is less clear which diet composition has the most beneficial effect during hypo-energetic dieting.

The objective of this study was, in a randomized intervention trial with obese subjects from eight centers in seven European countries, to examine if a 10-week low-fat hypo-energetic diet has a more beneficial effect on body weight, body composition and concentrations of fasting plasma lipids, glucose and insulin than a high-fat hypo-energetic diet.

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Subjects and methods

Protocol

The study was a randomized, parallel, two-arm, open-label 10-week dietary intervention of two hypo-energetic diets at eight sites in seven European countries: United Kingdom (England), The Netherlands, France (two centers), Spain, Czech Republic, Sweden and Denmark. The trial was part of a study of gene–nutrient interactions in the physiology and dietary treatment of obesity (see www.nugenob.org), in which it was planned to recruit 100 subjects from each center of the seven centers and 50 from one center. This would allow the study to detect 0.7 kg difference in weight loss, assuming a standard deviation (s.d.) of 4 kg, a significance P-value of 0.05 and a statistical power of 0.90.

Participants

We included 771 Caucasian Europeans (579 women). Inclusion criteria were body mass index greater than or equal to30 kg/m2 and age 20–50 years. Exclusion criteria were weight change >3 kg within the 3 months before the start of the study, hypertension, diabetes or hyperlipidemia treated by drugs, untreated thyroid disease, surgically or drug-treated obesity, pregnancy, participation in other trials, alcohol or drug abuse. However, some subjects were erroneously included despite a slightly lower BMI, and slightly greater antecedent weight loss, but a sensitivity analysis was conducted to examine the importance for the outcome (see statistical analysis). Analyses evaluating whether excluding the subjects who either had an inconsistent report of previous weight stability (n=82) or failed to meet one or more of the inclusion criteria for body mass index, fasting glucose, inconsistent bioimpedance measurement, medication, menopausal status or race (n=71) gave similar results, which are not presented. Participants were recruited through the media, from waiting lists, ongoing population studies, by self-referral or referral from a general physician or other clinical units and local obesity organizations. Recruitment of subjects was undertaken from May 2001 until September 2002. The study was approved by the Ethical Committee at each of the participating centers. Volunteers were informed about the nature of the study, and written consent was obtained before study participation.

Assignment

Stratified block randomization was used with center, gender and three age groups (20–29, 30–39 and 40–50 years) as strata and a block size of 12. The randomization list was computer generated and the block size was unknown to the clinical centers. Randomization was performed by contacting the coordinating center at each allocation (see details at www.nugenob.org).

Participant flow

The flow of participants is shown in Figure 1.

Figure 1.
Figure 1 - Unfortunately we are unable to provide accessible alternative text for this. If you require assistance to access this image, please contact help@nature.com or the author

Flow chart describing the progress of participants throughout the trial.

Full figure and legend (11K)

Diets

The target macronutrient composition of the two diets was as follows: low-fat diet – 20–25% of total energy from fat, 15% from protein and 60–65% from carbohydrate; high-fat diet – 40–45% of total energy from fat, 15% from protein and 40–45% from carbohydrate. Both diets were designed to provide 600 kcal/day (1 kilocalorie (kcal)=4.2 kilo joule (kJ)) less than the individually estimated energy requirement based on an initial resting metabolic rate multiplied by 1.3. Subjects were given oral and written instructions relating to these targets based on either a template (see details at www.nugenob.org) or an exchange system.13 Instructions were also given to minimize differences between the two diets in other components such as sources and type of fat, amount and type of fiber, type of carbohydrate, fruit and vegetables, and meal frequency. Subjects were requested to abstain from alcohol consumption. Dietary advice reflected local customs, and all food items were purchased by the subjects themselves. The dietary instructions were reinforced weekly. At each session, the dietician and the participant rated compliance with the dietary advice on a scale from 1 to 5, with perfect compliance equal to 1.

A 3-day-weighed food record of two weekdays and one weekend day was performed before the study and during the last week of the intervention. One-day-weighed food records were completed in the 2nd, 5th and 7th weeks. The dietary records were analyzed using the food–nutrient database routinely used in each center.

Anthropometry and metabolic rate

Body weights were measured on calibrated scales. Waist and hip circumferences were measured with the participant wearing only non-restrictive underwear. Body height was measured with a calibrated stadiometer. The mean of three measurements was recorded for each variable. Fat mass and fat-free mass were assessed by multifrequency bioimpedance (Bodystat®; QuadScan 4000, Isle of Man, British Isles). Resting metabolic rate was measured by ventilated hood systems routinely used at each center, and a standardized validation program was used to facilitate pooling of the results from the different centers.

Biochemical analyses

Venous blood samples were drawn after an overnight fast of 12 h, following a 3-day period when subjects had been instructed to avoid excessive physical activity or alcohol consumption. Subjects rested in the supine position for 15 min before the procedure. Fasting plasma glucose and lipid concentrations were measured with standard enzymatic techniques on a COBAS FARA centrifugal spectrophotometer (Roche Diagnostica, Basel, Switzerland; glucose HK 125, ABX Diagnostics, Montpellier, France; triglycerides, Sigma, St Louis, MO, USA; total cholesterol, cholesterol 100, ABX Diagnostics Montpellier France; HDL, HDL-C, Roche, IN, USA). Fasting plasma LDL-cholesterol was calculated using the formula of Friedewald et al.14 Fasting plasma insulin concentration was measured with a double-antibody radioimmunoassay (Insulin, RIA 100, Kabi-Pharmacia, Uppsala, Sweden). All biochemical analyses were conducted independently of the allocated intervention groups in core facilities at the Department of Human Biology, Nutrition Research Centre NUTRIM, Maastricht University, and Medical Laboratories Dr Stein & colleagues, Mönchengladbach, Germany.

Statistical analysis

The primary outcomes were mean weight loss and proportion of subjects who lost more than 10% of initial body weight, but we also analyzed the proportion of subjects who lost more than 5% of their initial body weight. The weight loss was calculated as the difference between the weight recorded immediately before randomization and the weight at the completion of the intervention program. Secondary outcomes were drop out, body composition, and blood lipids, insulin and glucose. Baseline differences were compared by an independent two-sample t-test. Differences in the changes were compared by univariate General Linear Models controlling for center and baseline value, and as appropriate with gender as covariate. To analyze changes within a group, paired samples t-tests were used. Variables with skewed distributions were log-transformed, and distributions were described by mean and s.d.. Testing of treatment effects on dichotomous outcomes (dropout rates and weight loss exceeding 5 and 10% of body weight) was performed by logistic regression allowing for both treatments, gender and center effects and using a robust estimation of the variance. Reasons for dropout were compared by chi2 test. The time courses of weight loss with the two diets were compared by repeated measurement analysis in General Linear Models. A thorough analysis of the impact on the estimated effects of the dietary regimens of the missing values, owing to the absence from some of the scheduled visits at the clinics and dropout, was conducted according to the methods recently suggested by Gadbury et al.15 This involved multiple imputation of the missing values and analysis by mixed linear models based on the assumption that values missing at random were conditional on the relevant observed values. In addition, a sensitivity analysis based on the assumptions of plausible deviant missing values in either direction of the results obtained was conducted. The outcomes of these analyses were essentially similar to those presented in the results section, and did not change the basis of the conclusions drawn from the results and are therefore not shown (they can be obtained on request). Statistical significance was set at P<0.05. The statistical software SPSS version 11.5, SAS version 8.2 and Stata version 8.0 were used.

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Results

The analyses were first conducted in men and women separately, and the results were presented for each gender. However, no significant differences in outcome were found between the two genders, and they were therefore also analyzed together.

Baseline characteristics and dropouts

The two groups were well matched at randomization (Table 1). Seventy (18.3%) failed to complete the 10-week high-fat intervention and only 53 (13.6%) failed to complete the low-fat intervention (P=0.001). Causes of dropout between the two groups were not statistically different and included change in personal circumstances, dislike of the diet and emerging health problems unrelated to the treatments. There were no clinically or statistically significant differences with respect to the variables listed in Table 1 between the participants who completed and those who did not, or between non-completers in the high- and the low-fat groups. The time point and the weight lost at dropout were not significantly different between the two groups.


Dietary intake

The self-reported, baseline dietary intake of the two groups was similar (Table 2). The fat energy percent during the interventions was within the targeted interval: 25% in the low-fat group and 40% in the high-fat group with a group difference of 16% (95% confidence interval (CI) 15–17%). Energy intake decreased to a slightly lower level in the low-fat group than in the high-fat group (P=0.023). The fiber intake was approximately 20% higher in the low-fat group than in the high-fat group (P<0.001). The percentage of energy from protein was slightly higher in the low fat diet, but total intake was not different. There was no difference between the compliance ratings for the two diets. The ratio of saturated to monounsaturated to polyunsaturated fatty acids was approximately 2:2:1 in the habitual diet and in the two intervention diets.


Body weight and body composition

Mean weight loss was 6.9 kg in the low, and 6.6 kg in the high-fat group with no group difference (mean 0.3 (95% CI -0.2 to 0.8) kg) (Table 3). The proportion of subjects who lost more than 5% was, on the low-fat diet 72.0% (242/336), and on the high-fat diet, 70.5% (220/312) (P=0.67). The proportion of subjects who lost 10% or more was greater in the low (20.8%, n=70) than in the high-fat group (14.7%, n=46; P=0.02) (Figure 2). There was no difference in the time course of weight loss during the 10 weeks between the groups (Figure 3). The changes in fat-free mass, fat mass, waist and hip circumference were not statistically different between the groups. In the intention-to-treat analysis, based on the principle of 'last observation carried forward' showed there was a 6.1% reduction of body weight in the low-fat group versus 5.4% in the high-fat group.

Figure 2.
Figure 2 - Unfortunately we are unable to provide accessible alternative text for this. If you require assistance to access this image, please contact help@nature.com or the author

Cumulative percentage weight loss during the 10-week intervention for the 648 subjects completing the 10-week intervention. The black line represents the low (n=336) and the dotted line the high-fat diet (n=312). On the x-axis, 0 represents a weight increase, 1 represents a weight loss of <1%, 2 represents a weight loss of <2%, and so on. The vertical line indicates the definition of the outcome of losing >10% of initial body weight, which was significantly different in the two groups (P=0.02).

Full figure and legend (13K)

Figure 3.
Figure 3 - Unfortunately we are unable to provide accessible alternative text for this. If you require assistance to access this image, please contact help@nature.com or the author

Mean weight change with 95% confidence interval for the 648 subjects completing the 10-week intervention on the low-fat diet (open squares, n=336) or the high-fat diet (filled squares, n=312). In weeks 1–9, the number of body weights recorded was less than 648.

Full figure and legend (12K)


Plasma lipids, glucose and insulin

The reduction of mean fasting plasma total cholesterol was 7.4% in the low versus 5.3% in the high-fat group (mean difference 2.2 (95% CI 0.4–4.0)%, P=0.016) (Table 4). Fasting plasma LDL-cholesterol was lowered by 7.8% in the low versus 4.7% in the high-fat group (mean difference 3.3 (95% CI 0.8–5.8)%, P=0.01). In the low-fat group, mean fasting plasma HDL-cholesterol was reduced by 7.3%, and by 2.4% in the high-fat group (mean difference 4.1 (95% CI 1.9–6.2)%, P<0.001). Mean fasting plasma triacylglycerol was lowered by 4.8% in the low and by 16.7% in the high-fat group (mean difference 5.7 (95% CI -0.5–11.8)%, P=0.07). There was no difference in the change between the two diets in LDL/HDL ratio (mean difference 0.02 (95% CI -0.09 to 0.11)%). Fasting plasma insulin and glucose concentrations were lowered similarly by both diets.


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Discussion

This 10-week randomized trial of two hypo-energetic diets with either low- or high-fat content, involving 771 obese subjects from eight centers in seven European countries, demonstrates that the two diets were not very different in producing a clinically significant weight loss in both women and men. There were however, in the low-fat group, fewer dropouts and a higher proportion of subjects who lost more than 10% of their initial body weight, than in the high-fat group. Fasting plasma total, LDL- and HDL-cholesterol were lowered more in the low-fat group, whereas fasting plasma insulin and glucose decreased equally in the two groups.

To minimize misreporting,16, 17, 18 we carefully trained subjects in completing weighed food records. In order to prevent bias introduced by the enthusiasm of the dietician providing the intervention,8 careful attention was paid to standardizing the delivery method of the dietary programs.

Based on the differences between fat and carbohydrate in digestibility and thermogenic effect, and interactions between diet composition and exercise, it has been suggested that low-fat diets are superior to higher fat diets in producing a weight loss.19, 20 Short-term test meal studies with calorie for calorie comparisons suggest that carbohydrate is more satiating than fat and that overeating may be more likely with a high-fat diet because of the higher energy density and greater sensory pleasure.21, 22 The present study demonstrates that these potential differences produced by energy-fixed diets with various fat and carbohydrate contents do not translate into overall weight loss differences, but may contribute to explain why more subjects lost >10% of the initial body weight in the low-fat group. However, it is important to stress that the study duration of only 10 weeks was relatively short in the course of a weight management program, and diet palatability and tolerability might have more important influence on weight loss outcome in long-term studies.

Other studies suggest that diets high in protein and fat, but with very low carbohydrate contents, might be more satiating, and produce better weight loss than low-fat diets with normal protein content.4 However, it is very likely that the high protein content rather than the high-fat content is responsible for the weight loss effect with these diets.7 Our results suggest that a larger proportion of obese subjects achieve a major weight loss, that is, more than 10%, and fewer will drop out on the low-fat diet. This is in line with previous ad libitum studies,4, 5, 6 and suggests that energy from carbohydrate are slightly more satiating than those from fat also under conditions with a fixed energy deficit.

We did find a slightly greater reduction in energy intake in the low- compared with the moderate-fat group, which may be attributed to a greater satiating effect of the low-fat diet. The difference of 60 kcal/day during a 10-week period corresponds to a difference in weight loss of approx0.54 kg,23 which is within the 95% CI of the difference in weight loss among completers (-0.2–0.8 kg). The slightly lower weight loss in the high-fat diet may also be explained by the contrast with subjects' expectations regarding dietary weight loss regimens, and the challenge of providing an acceptable high-fat diet. This may also explain the lower rate of dropout in the low-fat diet group. In this study, a larger weight loss has been achieved than in most other studies. The intervention package included prescribed energy intake based upon an individually measured resting metabolic rate in contrast to others who used a fixed energy intake target.7, 8 A tailored dietary program was used, in contrast to one other study, which used a limited menu cycle,6 and a high level of support was offered to the subjects.

The effect of the diets on blood lipids was as expected from other studies.8, 24 The slight reduction observed in HDL-cholesterol is very likely owing to the negative energy balance at the time of measurement. The effect of diet per se on HDL-cholesterol cannot be seen before the subject are weight stable. In previous studies, the undesirable reduction in HDL-cholesterol brought about by a low-fat diet had returned to baseline concentration by 6 months.8 Other studies with smaller subject numbers showed either a limited7 or no effect.6 The decrease in the blood lipids is primarily a result of the weight loss per se. The present study additionally demonstrates that both diets have beneficial effects on blood lipids.

This study shows that when intensive support is given, dietary advice of a hypo-energetic high-fat diet adhered to during 10 weeks is almost as effective as a low-fat diet in producing weight loss. However, more subjects lost >10% of initial body weight on the low fat diet and fewer dropped out. Both diets produced beneficial changes in the fasting blood lipid profile, plasma insulin and glucose.

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Notes

Conflict of interest

None of the authors have any conflict of interest.

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References

  1. Obesity: Preventing and Managing the Global Epidemic. Report of a WHO Consultation Technical Report Series, 2000.
  2. Tuomilehto J, Lindstrom J, Eriksson JG, Valle TT, Hamalainen H, Ilanne-Parikka P et al., Finnish Diabetes Prevention Study Group. Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance. N Engl J Med 2001; 344: 1343–1350. | Article | PubMed | ISI | ChemPort |
  3. Knowler WC, Barrett-Connor E, Fowler SE, Hamman RF, Lachin JM, Walker EA et al., Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med 2002; 346: 393–403. | Article | PubMed | ISI | ChemPort |
  4. Astrup A, Grunwald GK, Melanson EL, Saris WHM, Hill JO. The role of low-fat diets in body weight control: a meta-analysis of ad libitum intervention studies. Int J Obes Relat Metab Disord 2000; 24: 1545–1552. | Article | PubMed | ChemPort |
  5. Toubro S, Astrup A. Randomised comparison of diets for maintaining obese subjects' weight after major weight loss: ad lib, low fat, high carbohydrate diet v fixed energy intake. BMJ 1997; 314: 29–34. | PubMed | ChemPort |
  6. Saris WHM, Astrup A, Prentice AM, Zunft HJH, Formiguera X, Verboeket-van de Venne WPHG et al. Randomized controlled trial of changes in dietary carbohydrate/fat ratio and simple vs complex carbohydrates on body weight and blood lipids: the CARMEN study. Int J Obes Relat Metab Disord 2000; 24: 1310–1318. | Article | PubMed | ChemPort |
  7. Due A, Toubro S, Skov AR, Astrup A. Effect of normal-fat diets, either medium or high in protein, on body weight in overweight subjects: a randomised 1-year trial. Int J Obes Relat Metab Disord 2004; 28: 1283–1290. | Article | PubMed | ChemPort |
  8. Golay A, Eigenheer C, Morel Y, Kujawski P, Lehmann T, de Tonnac N. Weight-loss with low or high carbohydrate diet? Int J Obes Relat Metab Disord 1996; 20: 1067–1072. | PubMed | ChemPort |
  9. Lean ME, Han TS, Prvan T, Richmond PR, Avenell A. Weight loss with high and low carbohydrate 1200 kcal diets in free living women. Eur J Clin Nutr 1997; 51: 243–248. | Article | PubMed | ISI | ChemPort |
  10. Mensink RP, Katan MB. Effect of dietary fatty acids on serum lipids and lipoproteins. A meta-analysis of 27 trials. Arterioscler Thromb 1992; 12: 911–919. | PubMed | ISI | ChemPort |
  11. Mensink RP, Zock PL, Kester AD, Katan MB. Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: a meta-analysis of 60 controlled trials. Am J Clin Nutr 2003; 77: 1146–1155. | PubMed | ISI | ChemPort |
  12. Bisschop PH, de Metz J, Ackermans MT, Endert E, Pijl H, Kuipers F et al. Dietary fat content alters insulin-mediated glucose metabolism in healthy men. Am J Clin Nutr 2001; 73: 554–559. | PubMed | ISI | ChemPort |
  13. Verdich C, Madsen JL, Toubro S, Buemann B, Holst JJ, Astrup A. Effect of obesity and major weight reduction on gastric emptying. Int J Obes Relat Metab Disord 2000; 24: 899–905. | Article | PubMed | ChemPort |
  14. Friedewald WT, Levy RI, Fredrickson DS. Estimation of the concentration of low-density lipoprotein cholesterol in plasma, without use of the preparative ultracentrifuge. Clin Chem 1972; 18: 499–502. | PubMed | ISI | ChemPort |
  15. Gadbury GL, Coffey CS, Allison DB. Modern statistical methods for handling missing repeated measurements in obesity trial data: beyond LOCF. Obes Rev 2003; 4: 175–184. | Article | PubMed | ChemPort |
  16. Prentice AM, Black AE, Coward WA, Davies HL, Goldberg GR, Murgatroyd PR et al. High levels of energy expenditure in obese women. BMJ 1986; 292: 983–987. | PubMed | ChemPort |
  17. Goris AH, Westerterp-Plantenga MS, Westerterp KR. Undereating and underrecording of habitual food intake in obese men: selective underreporting of fat intake. Am J Clin Nutr 2000; 71: 130–134. | PubMed | ISI | ChemPort |
  18. Heitmann BL. The influence of fatness, weight change, slimming history and other lifestyle variables on diet reporting in Danish men and women aged 35–65 years. Int J Obes Relat Metab Disord 1993; 17: 329–336. | PubMed | ChemPort |
  19. Stubbs RJ, Prentice AM, James WP. Carbohydrates and energy balance. Ann NY Acad Sci 1997; 819: 44–69. | PubMed | ChemPort |
  20. Helge JW. Long-term fat diet adaptation effects on performance, training capacity, and fat utilization. Med Sci Sports Exerc 2002; 34: 1499–1504. | Article | PubMed | ISI | ChemPort |
  21. Stubbs RJ, Ritz P, Coward WA, Prentice AM. Covert manipulation of the ratio of dietary fat to carbohydrate and energy density: effect on food intake and energy balance in free-living men eating ad libitum. Am J Clin Nutr 1995; 62: 330–337. | PubMed | ISI | ChemPort |
  22. Blundell JE, Stubbs RJ. High and low carbohydrate and fat intakes: limits imposed by appetite and palatability and their implications for energy balance. Eur J Clin Nutr 1999; 53: S148–S165. | Article | PubMed | ISI |
  23. Bouchard C, Tremblay A. Genetic influences on the response of body fat and fat distribution to positive and negative energy balances in human identical twins. J Nutr 1997; 127: S943–S947. | ISI |
  24. Leenen R, van der KK, Meyboom S, Seidell JC, Deurenberg P, Weststrate JA. Relative effects of weight loss and dietary fat modification on serum lipid levels in the dietary treatment of obesity. J Lipid Res 1993; 34: 2183–2191. | PubMed | ISI | ChemPort |
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Appendices

Appendix A. Contributorship of the authors and the NUGENOB Consortium

Project partners: 1: Institute of Preventive Medicine, Danish Epidemiology Science Centre, Copenhagen University Hospital, Copenhagen, Denmark; 2: Department of Human Nutrition, The Royal Veterinary and Agricultural University, Copenhagen, Denmark; 3: Steno Diabetes Centre, Gentofte, Denmark; 4: Department of Human Genetics, Institute of Biology, Institute Pasteur de Lille, France; 5: Department of Human Biology, Nutrition and Toxicology Research Centre NUTRIM, Maastricht University, Maastricht, The Netherlands; 6: The Lipid Laboratory, Department of Medicine, Karolinska Institute, Huddinge University Hospital, Sweden; 7: The Obesity Unit, Department of Medicine, Karolinska Institute, Huddinge University Hospital, Sweden; 8: School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK; 9: Department of Sports Medicine, Centre of Preventive Medicine, Third Faculty of Medicine, Charles University, Praha, Czech Republic; 10: Department of Nutrition, Hôtel-Dieu, Paris, France; 11: Obesity Research Unit Inserm U586, Louis Bugnard Institute and Clinical Investigation Centre, Toulouse University Hospitals, Paul Sabatier University, Toulouse, France; 12: Department Physiology and Nutrition, University of Navarra, Pamplona, Spain.

Project Steering Committee: Thorkild IA Sørensen (chair)1, Arne Astrup2, Oluf Pedersen3, Philippe Froguel4, Wim HM Saris5, Peter Arner6, Stephan Rössner7, Ian Macdonald8, Vladimir Stich9, Bernard Guy-Grand10, Dominique Langin11, Alfredo J Martinez12. Camilla Verdich1, Søren Toubro2 and Søren M Echwald3 were associated co-ordinating members of the committee.

Project Co-ordination: Thorkild IA Sørensen (project co-ordinator)1, Camilla Verdich (assistant co-ordinator)1, Gabby Hul (co-ordinator of biobank procedures)5, Moira A Taylor (co-ordinator of dietary assessment and intervention)8, Claus Holst (senior statistician)1, Lene Aa Hansen (administrator)1 and Birgitte Bredesen (secretary)1.

Work package responsibility: Thorkild IA Sørensen (study population and recruitment, database and statistical analysis)1, Wim HM Saris (baseline clinical investigation)5 and Arne Astrup (dietary intervention)2.

Development of standard operational procedures: Thorkild IA Sørensen (study population, recruitment)1, Søren Toubro (in–exclusion criteria)2, Claus Holst (randomization)1, Gabby Hul (baseline clinical investigation)5, Moira A Taylor (dietary assessment and intervention)8 and Camilla Verdich (database management)1.

Clinical investigators group: Arne Astrup2, Martin Petersen2, Søren Toubro2, Kirsten Bryde Resmussen2, Wim HM Saris5, Ellen Blaak5, Gabby Hul5, Patrik Löfgren6, Ingalena Andersson7, Gun Åberg7, Ian Macdonald8, Moira A Taylor8, Sue Bridgewater8, Jonathan Webber8, Kishor Patel8, Vladimir Stich9, Blanka Richterova9, Petra Sramkova9, Bernard Guy-Grand10, Jean-Michel Oppert10, Pierre Barbe11, Alfredo J Martinez12 and Idoia Labayen12.

Biobank and laboratory analysis group: Gabby Hul5, Ellen Blaak5, Jos Stegen5 and Wim HM Saris5.

Dietitian group: Gitte Wenneberg2, Tine B Christensen2, Ulla Pedersen2, Marja van der Hulst5, Brigit Rooyakkers5, Ingalena Andersson7, Gun Åberg7, Sue Bridgewater8, Moira A Taylor (chair)8, Eva Chocenska9, Blanka Richterova9, Vladimira Smejkalova9, Maelle Coustillet10, Françoise L'Hôte11, Idoia labayen12 and Iva Marques12.

Database management: Claus Holst1 and Camilla Verdich1.

Statistical analysis: Claus Holst1, Martin Petersen2, Moira A Taylor8, Camilla Verdich1, Liselotte Petersen1 and Thorkild IA Sørensen1.

Manuscript drafting: Martin Petersen2, Moira A Taylor (equal with Martin Petersen)8, Camilla Verdich1, Søren Toubro2, Claus Holst1, Ian Macdonald8, Thorkild IA Sørensen1 and Arne Astrup2.

Manuscript revision for important content: Oluf Pedersen3, Wim HM Saris5, Stephan Rössner7, Vladimir Stich9, Bernard Guy-Grand10, Dominique Langin11 and Alfredo J Martinez12.

Guarantor: Thorkild IA Sørensen1.

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Acknowledgements

The study was supported by the European Community (Contract no. QLK1-CT-2000-00618). The funding organization had no role in the preparation of the manuscript.

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