Fructose prefeeding reduces the glycemic response to a high-glycemic index, starchy food in humans

Abstract

The study objective was to determine whether a small dose of fructose administered before or simultaneously with a high glycemic index, starchy food decreases postprandial glycemic response. Nondiabetic healthy adults (n = 31; mean ± SEM: age, 26 ± 1 y; weight, 66.1 ± 2.6 kg; body mass index, 23.3 ± 0.6 kg/m2) were studied in a randomized crossover design. Treatments consisted of 50 g available carbohydrate from instant mashed potatoes fed alone (control) or with 10 g fructose fed 60, 30 or 0 min before the potato meal. Capillary finger-stick blood samples were analyzed for glucose concentration at -60, -30, 0, 15, 30, 45, 60, 90 and 120 min relative to the ingestion of the potato meal. Compared with the control, the positive incremental area under the glucose curve was reduced 25 and 27% (P < 0.01) when fructose was fed either 60 or 30 min before the meal, respectively. In contrast to previous studies demonstrating that immediate administration of a small amount of fructose lowers the glycemic response to a glucose solution, we found that fructose must be consumed before a starchy food to reduce postprandial glycemia.