Influence of Glycemic Index/Load on Glycemic Response, Appetite, and Food Intake in Healthy Humans

Abstract

OBJECTIVE—High glycemic index (GI)/load (GL) diets reportedly enhance appetite and promote positive energy balance. Support for this hypothesis stems largely from acute feeding trials and longer-term studies lacking control over the macronutrient composition and palatability of test foods. This study evaluated the effects of consuming high- and low-GI/GL meals, matched on macronutrient composition and palatability, plasma glucose and insulin, appetite, and food intake. RESEARCH DESIGN AND METHODS—Thirty-nine healthy adults consumed only low- or only high-GI foods ad libitum in the laboratory for 8 days in either high (three foods per meal)- or low (one food per meal)-variety conditions. Glucose and insulin concentrations as well as appetitive sensations were determined before and for 2 h following breakfast and lunch on days 1 and 8. Energy intake was monitored daily. RESULTS—There were no significant differences in plasma glucose or insulin responses, appetitive ratings, or food intake between treatments. CONCLUSIONS—These data indicate that the differential glycemic response of foods tested in isolation under fixed time are not preserved under conditions of chronic ad libitum consumption of mixed meals.