Effect of Resistant Starch (RS) Wheat Supplementation on Satiety

The objective of this analysis is to determine whether intake of wheat products high in resistant starch (RS) increase satiety relative to conventional wheat products via blunting of the glycemic response and stimulation of hormones such as glucose-dependent insulinotropic polypeptide (GIP), peptide YY (PYY), glucagon-like peptide-1 (GLP-1), leptin, or ghrelin. Metabolic responses generated from a double-blind, placebo controlled, crossover clinical trial of RS and regular wheat were used to investigate whether RS supplementation affects subjective and objective measures of satiety relative to conventional wheat. Women and men consumed 3 or 4 rolls per day, respectively, made from RS (14–18 g total dietary fiber, TDF) or conventional wheat (4–5.5 g TDF) for 7 days during each arm of the trial. Linear mixed models of glycemic and satiety outcomes were used to determine the effect RS supplementation. A total of 30 healthy adults ages 40–65 completed the study. We observed a significant effect of RS wheat on glycemic response such that postprandial glucose and insulin incremental area under the curve (iAUC) during RS supplementation were lower than during regular wheat consumption (P = 0.004, P < 0.001, respectively). Biological indicators of satiety showed lower iAUC and peak GIP (piAUC < 0.001, ppeak < 0.001) as well as higher fasting and peak PYY (pfasting = 0.004, ppeak = 0.004). There were no significant effects of treatment observed for ghrelin, leptin, or GLP-1. Additionally, there were no significant effects of treatment on subjective measures of fullness or hunger during test days (P = 0.57 and P = 0.20, respectively). The results of this analysis indicate that RS supplementation is effective at blunting the postprandial glycemic response but has marginal effects on objective and subjective measures of satiety. Further research is needed to determine the potential effects of providing RS in different doses, volumes (e.g., supplement versus whole food), food matrix (e.g., pasta versus rolls), or duration of exposure on satiety. Funding was provided by the University of California Innovation Institute for Food and Health with gifts from Arcadia Biosciences and Ardent Mills.