Relation between estimates of cornstarch digestibility by the Englyst in vitro method and glycemic response, subjective appetite, and short-term food intake in young men

Abstract

Starch composition and rate of digestion are determinants of blood glucose concentrations and food intake (FI). Our objective was to describe relations between estimates of digestibility of starches by the in vitro Englyst method and their effect on blood glucose concentrations, subjective appetite, and FI in young men. Subjects consumed 5 soups containing 50 g maltodextrin, whole-grain, high-amylose, regular cornstarch, or no added starch at 1-wk intervals. Ad libitum FI was measured at 30 min (experiment 1) or 120 min (experiment 2) later, which were the estimated times of digestion of a rapidly digestible starch (RDS) and slowly digestible starch, respectively. Blood glucose concentrations and appetite were measured pre- and postmeal. At 30 min, FI was reduced by maltodextrin only [86% RDS, 12% resistant starch (RS); P < 0.05], but at 120 min FI was reduced by whole-grain (24% RDS, 66% RS), high-amylose corn (40% RDS, 48% RS), and regular corn (27% RDS, 39% RS) (P < 0.0001). The premeal blood glucose concentration at 30 and 120 min was highest and lowest after maltodextrin treatment, respectively (P < 0.0001). After the meal, the blood glucose area under the curve at 30 min was lower after all starch treatments (P < 0.05), but at 120 min the blood glucose area under the curve was lower only after the regular cornstarch treatment (P < 0.05). Premeal appetite decreased by all treatments (P < 0.05). The in vitro estimates of starch digestibility by the Englyst method predicted the effects of starch composition on blood glucose concentrations and FI in young men 30 and 120 min after consumption. This trial was registered at clinicaltrials.gov as NCT00980941 for experiment 1 and NCT00988689 for experiment 2.