title: Glycogen storage capacity and de novo lipogenesis during massive carbohydrate overfeeding in man.
abstract: The metabolic balance method was performed on three men to investigate the fate of large excesses of carbohydrate. Glycogen stores, which were first depleted by diet (3 d, 8.35 +/- 0.27 MJ [1994 +/- 65 kcal] decreasing to 5.70 +/- 1.03 MJ [1361 +/- 247 kcal], 15% protein, 75% fat, 10% carbohydrate) and exercise, were repleted during 7 d carbohydrate overfeeding (11% protein, 3% fat, and 86% carbohydrate) providing 15.25 +/- 1.10 MJ (3642 +/- 263 kcal) on the first day, increasing progressively to 20.64 +/- 1.30 MJ (4930 +/- 311 kcal) on the last day of overfeeding. Glycogen depletion was again accomplished with 2 d of carbohydrate restriction (2.52 MJ/d [602 kcal/d], 85% protein, and 15% fat). Glycogen storage capacity in man is approximately 15 g/kg body weight and can accommodate a gain of approximately 500 g before net lipid synthesis contributes to increasing body fat mass. When the glycogen stores are saturated, massive intakes of carbohydrate are disposed of by high carbohydrate-oxidation rates and substantial de novo lipid synthesis (150 g lipid/d using approximately 475 g CHO/d) without postabsorptive hyperglycemia.
authors.affiliation: Institute of Physiology, Faculty of Medicine, University of Lausanne, Switzerland.
authors.forename: K J
authors.initials: KJ
authors.lastname: Acheson
authors.forename: Y
authors.initials: Y
authors.lastname: Schutz
authors.forename: T
authors.initials: T
authors.lastname: Bessard
authors.forename: K
authors.initials: K
authors.lastname: Anantharaman
authors.forename: J P
authors.initials: JP
authors.lastname: Flatt
authors.forename: E
authors.initials: E
authors.lastname: Jéquier
mesh_terms: D000328:Adult; D001823:Body Composition; D002153:Calorimetry, Indirect; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D002149:Energy Intake; D004734:Energy Metabolism; D001068:Feeding and Eating Disorders / Q000378:metabolism*; D006003:Glycogen / Q000378:metabolism*; D006801:Humans; D006963:Hyperphagia / Q000378:metabolism*; D008055:Lipids / Q000096:biosynthesis*; D008297:Male; D012016:Reference Values
chemical_list: D004040:Dietary Carbohydrates; D008055:Lipids; D006003:Glycogen