title: Carbohydrate intake and glycemic index affect substrate oxidation during a controlled weight cycle in healthy men.
abstract: OBJECTIVE
  Because both, glycemic index (GI) and carbohydrate content of the diet increase insulin levels and could thus impair fat oxidation, we hypothesized that refeeding a low GI, moderate-carbohydrate diet facilitates weight maintenance.
  
  
  METHODS
  Healthy men (n=32, age 26.0±3.9 years; BMI 23.4±2.0 kg/m(2)) followed 1 week of controlled overfeeding, 3 weeks of caloric restriction and 2 weeks of hypercaloric refeeding (+50, -50 and +50% energy requirement) with low vs high GI (41 vs 74) and moderate vs high CHO intake (50% vs 65% energy). We measured adaptation of fasting macronutrient oxidation and the capacity to supress fat oxidation during an oral glucose tolerance test. Changes in fat mass were measured by quantitative magnetic resonance.
  
  
  RESULTS
  During overfeeding, participants gained 1.9±1.2 kg body weight, followed by a weight loss of -6.3±0.6 kg and weight regain of 2.8±1.0 kg. Subjects with 65% CHO gained more body weight compared with 50% CHO diet (P<0.05) particularly with HGI meals (P<0.01). Refeeding a high-GI diet led to an impaired basal fat oxidation when compared with a low-GI diet (P<0.02), especially at 65% CHO intake. Postprandial metabolic flexibility was unaffected by refeeding at 50% CHO but clearly impaired by 65% CHO diet (P<0.05). Impairment in fasting fat oxidation was associated with regain in fat mass (r=0.43, P<0.05) and body weight (r=0.35; P=0.051).
  
  
  CONCLUSIONS
  Both higher GI and higher carbohydrate content affect substrate oxidation and thus the regain in body weight in healthy men. These results argue in favor of a lower glycemic load diet for weight maintenance after weight loss.
authors.affiliation: Institute of Nutritional Medicine, University Hohenheim, Stuttgart, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Kahlhöfer
authors.affiliation: Institute of Human Nutrition and Food Science, Christian-Albrechts-University of Kiel, Kiel, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Lagerpusch
authors.affiliation: Institute of Human Nutrition and Food Science, Christian-Albrechts-University of Kiel, Kiel, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Enderle
authors.affiliation: Institute of Human Nutrition and Food Science, Christian-Albrechts-University of Kiel, Kiel, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Eggeling
authors.affiliation: Institute of Human Nutrition and Food Science, Christian-Albrechts-University of Kiel, Kiel, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Braun
authors.affiliation: InsuLean GmbH & Co. KG, Essen, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Pape
authors.affiliation: Institute of Human Nutrition and Food Science, Christian-Albrechts-University of Kiel, Kiel, Germany.
authors.forename: M J
authors.initials: MJ
authors.lastname: Müller
authors.affiliation: 1] Institute of Nutritional Medicine, University Hohenheim, Stuttgart, Germany [2] Institute of Human Nutrition and Food Science, Christian-Albrechts-University of Kiel, Kiel, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Bosy-Westphal
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D001835:Body Weight / Q000187:drug effects; D031204:Caloric Restriction; D004032:Diet; D004040:Dietary Carbohydrates / Q000008:administration & dosage* / Q000378:metabolism / Q000494:pharmacology; D004041:Dietary Fats / Q000378:metabolism*; D002149:Energy Intake; D005951:Glucose Tolerance Test; D038321:Glycemic Index; D006801:Humans; D008297:Male; D010084:Oxidation-Reduction; D019518:Postprandial Period; D012016:Reference Values; D015430:Weight Gain; D015431:Weight Loss; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004041:Dietary Fats