Title: Glucose Metabolism and Insulin Sensitivity Were Unaffected by Dietary Fructose Intake (And Glycemic Index) in Obese and Lean Adolescents Authors
Submitted to: Pediatric Academic Society
Publication Type: Abstract Only
Publication Acceptance Date: December 15, 2004
Publication Date: May 16, 2005
Citation: Sunehag, A.L., Toffolo, G., Bier, D.M., Haymond, M. 2005. Glucose metabolism and insulin sensitivity were unaffected by dietary fructose intake (and glycemic index) in obese and lean adolescents [abstract]. Pediatric Academic Societies. 57:786 Technical Abstract: There is growing concern that the increased consumption of fructose has detrimental effects on carbohydrate metabolism in adolescents. This study was designed to determine whether a high dietary fructose intake consumed over the short term adversely affects glucose metabolism, insulin secretion or sensitivity, and blood lipids. Six obese Tanner V adolescents (15.2 +/-0.5 y; 35.0 +/-1.9 kg/m2; 39 +/-2 % body fat) were studied twice following 7 d of isocaloric, isonitrogenous diets providing 25% of dietary energy intake as fat and 60% as CHO; the latter consisting of either 10% (LF) or 40% fructose (HF), representing either 6% or 24% of dietary energy intake as fructose. The corresponding Glycemic Indices (GI) were 60 and 51. Glucose production was measured by [13C]glucose and insulin secretion and sensitivity were modeled by the stable labeled intravenous glucose tolerance test. The data were compared to those obtained in 12 lean, Tanner V adolescents (14.8 +/-0.4 y; 20.5 +/-0.7 kg/m2; 15.7 +/-2.4 % body fat) previously studied under identical conditions. RESULTS: Obese subjects were insulin resistant irrespective of dietary fructose content and remained normoglycemic by increasing insulin secretion. Notwithstanding this body fat effect, glucose production, insulin secretion, insulin sensitivity, and triglyceride concentrations were unaffected by four-fold increase in dietary fructose intake, either in the lean or in the obese adolescents. Nor was there an effect of GI, although the LF diet had a GI that was only 18% higher than the HF diet. Consumed over the short term, wide variation in dietary fructose intake has no demonstrable effect on glucose production, insulin secretion, or insulin sensitivity in either lean or obese adolescents.