Comparison of 3 ad libitum diets for weight-loss maintenance, risk of cardiovascular disease, and diabetes: a 6-mo randomized, controlled trial.
BACKGROUND
The optimal dietary content and type of fat and carbohydrate for weight management has been debated for decades.


OBJECTIVE
The objective was to compare the effects of 3 ad libitum diets on the maintenance of an initial weight loss of >or=8% and risk factors for CVD and diabetes during a 6-mo controlled dietary intervention.


METHODS
Nondiabetic overweight or obese [mean +/- SD body mass index (in kg/m(2)): 31.5 +/- 2.6] men (n = 55) and women (n = 76) aged 28.2 +/- 4.8 y were randomly assigned to a diet providing a moderate amount of fat (35-45% of energy) and >20% of fat as monounsaturated fatty acids (MUFA diet; n = 54), to a low-fat (20-30% of energy) diet (LF diet; n = 51), or to a control diet (35% of energy as fat; n = 26). Protein constituted 10-20% of energy in all 3 diets. All foods were provided free of charge from a purpose-built supermarket.


RESULTS
More subjects dropped out of the MUFA (28%) group than out of the LF group (16%) and control group (8%) (MUFA compared with control: P < 0.05). All groups regained weight (MUFA: 2.5 +/- 0.7 kg; LF: 2.2 +/- 0.7 kg; and control: 3.8 +/- 0.8 kg; NS). Body fat regain was lower in the LF (0.6 +/- 0.6%) and MUFA (1.6 +/- 0.6%) groups than in the control group (2.6 +/- 0.5%) (P < 0.05). In the MUFA group, fasting insulin decreased by 2.6 +/- 3.5 pmol/L, the homeostasis model assessment of insulin resistance by 0.17 +/- 0.13, and the ratio of LDL to HDL by 0.33 +/- 0.13; in the LF group, these variables increased by 4.3 +/- 3.0 pmol/L (P < 0.08) and 0.17 +/- 0.10 (P < 0.05) and decreased by 0.02 +/- 0.09 (P = 0.005), respectively; and in the control group, increased by 14.0 +/- 4.3 pmol/L (P < 0.001), 0.57 +/- 0.17 (P < 0.001), and 0.05 +/- 0.14 (P = 0.036), respectively. Dietary adherence was high on the basis of fatty acid changes in adipose tissue.


CONCLUSIONS
Diet composition had no major effect on preventing weight regain. However, both the LF and MUFA diets produced less body fat regain than did the control diet, and the dropout rate was lowest in the LF diet group, whereas fasting insulin decreased and the homeostasis model assessment of insulin resistance and ratio of LDL to HDL improved with the MUFA diet. This trial was registered at clinicaltrials.gov as NCT00274729.
Due
Anette
A
Department of Human Nutrition, Centre for Advanced Food Studies, Faculty of Life Sciences, University of Copenhagen, Frederiksberg C, Denmark.
Larsen
Thomas M
TM
Mu
Huiling
H
Hermansen
Kjeld
K
Stender
Steen
S
Astrup
Arne
A
D000293:Adolescent; D000328:Adult; D001481:Basal Metabolism / Q000502:physiology; D001786:Blood Glucose / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000097:blood / Q000453:epidemiology*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000453:epidemiology*; D004038:Diet, Reducing; D004040:Dietary Carbohydrates / Q000008:administration & dosage* / Q000378:metabolism; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage* / Q000378:metabolism; D002149:Energy Intake / Q000502:physiology; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D050356:Lipid Metabolism / Q000502:physiology; D008297:Male; D009765:Obesity / Q000097:blood / Q000178:diet therapy* / Q000453:epidemiology; D010349:Patient Compliance; D016896:Treatment Outcome; D015431:Weight Loss / Q000502:physiology*
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004042:Dietary Fats, Unsaturated; D007328:Insulin