Effect of Calorie Restriction With or Without Exercise on Insulin Sensitivity, β-Cell Function, Fat Cell Size, and Ectopic Lipid in Overweight Subjects

• DOI: 10.2337/dc05-2565
• Publication Date: 2006-05-26T20:32:06Z
• Authors: D. Enette Larson-...; Leonie K. Heilbronn; Leanne M. Redman; Bradley R. Newcomer; Madlyn I. Frisard; Steve Anton; Steven R. Smith; Anthony Alfonso; Eric Ravussin
• Keywords: Calorie Restriction

OBJECTIVE—The purpose of this article was to determine the relationships among total body fat, visceral adipose tissue (VAT), fat cell size (FCS), ectopic deposition in liver (intrahepatic lipid [IHL]) and muscle (intramyocellular [IMCL]), insulin sensitivity index (Si) healthy overweight, glucose-tolerant subjects effects calorie restriction by diet alone or conjunction with exercise on these variables. RESEARCH DESIGN AND METHODS—Forty-eight overweight volunteers were randomly assigned four groups: control (100% energy requirements), 25% (CR), 12.5% +12.5% expenditure through structured (CREX), 15% weight loss a low-calorie followed maintenance for 6 months (LCD). Weight, percent VAT, IMCL, IHL, FCS, Si assessed at baseline month 6. RESULTS—At baseline, FCS related VAT IHL (P < 0.05) but not IMCL. also strongest determinant 0.01). Weight 1 ± 1% (control, mean SE), 10 14 reduced three intervention groups 0.01), IMCL unchanged. increased = CREX (37 18%) LCD (70 34%) tended increase CR group (40 20%, P 0.08). Together improvements weight, mass, FCS. CONCLUSIONS—Large adipocytes lead hepatic tissues, promoting resistance. Calorie reverses trend.