Influence of glycemic index/load on glycemic response, appetite, and food intake in healthy humans.

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.