title: The effect of a low-fat, high-protein or high-carbohydrate ad libitum diet on weight loss maintenance and metabolic risk factors.
abstract: BACKGROUND
  High-protein (HP) diets are often advocated for weight reduction and weight loss maintenance.
  
  
  OBJECTIVE
  The aim was to compare the effect of low-fat, high-carbohydrate (HC) and low-fat, HP ad libitum diets on weight maintenance after weight loss induced by a very low-calorie diet, and on metabolic and cardiovascular risk factors in healthy obese subjects.
  
  
  METHODS
  Forty-eight subjects completed the study that consisted of an energy restriction period of 5-6 weeks followed by a weight maintenance period of 12 weeks. During weight maintenance subjects received maltodextrin (HC group) or protein (HP group) (casein (HPC subgroup) or whey (HPW subgroup)) supplements (2 x 25 g per day), respectively and consumed a low-fat diet.
  
  
  RESULTS
  Subjects in the HP diet group showed significantly better weight maintenance after weight loss (2.3 kg difference, P=0.04) and fat mass reduction (2.2 kg difference, P=0.02) than subjects in the HC group. Triglyceride (0.6 mM difference, P=0.01) and glucagon (9.6 pg ml(-1) difference, P=0.02) concentrations increased more in the HC diet group, while glucose (0.3 mM difference, P=0.02) concentration increased more in the HP diet group. Changes in total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, insulin, HOMAir index, HbA1c, leptin and adiponectin concentrations did not differ between the diets. No differences were found between the casein- or whey-supplemented HP groups.
  
  
  CONCLUSIONS
  These results show that low-fat, high-casein or whey protein weight maintenance diets are more effective for weight control than low-fat, HC diets and do not adversely affect metabolic and cardiovascular risk factors in weight-reduced moderately obese subjects without metabolic or cardiovascular complications.
authors.affiliation: Department of Human Biology, Nutrition and Toxicology Research institute Maastricht, Maastricht University, Maastricht, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Claessens
authors.forename: M A
authors.initials: MA
authors.lastname: van Baak
authors.forename: S
authors.initials: S
authors.lastname: Monsheimer
authors.forename: W H M
authors.initials: WH
authors.lastname: Saris
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000517:prevention & control; D003925:Diabetic Angiopathies / Q000097:blood / Q000178:diet therapy* / Q000517:prevention & control; D018752:Diet, Fat-Restricted / Q000009:adverse effects; D004038:Diet, Reducing / Q000009:adverse effects; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000009:adverse effects; D004044:Dietary Proteins / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000517:prevention & control; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000150:complications / Q000178:diet therapy*; D011134:Polysaccharides / Q000008:administration & dosage / Q000009:adverse effects; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood; D015431:Weight Loss / Q000502:physiology
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D011134:Polysaccharides; D014280:Triglycerides; C008315:maltodextrin