Consuming Chilled Russet Potatoes High in Resistant Starch Improves Postprandial Insulin and Glucose-dependent Insulinotropic Peptide in Overweight Females (P08-089-19)

Abstract

Abstract Objectives Resistant starch (RS) is an insoluble, fermentable, and indigestible fiber found naturally in potatoes that can improve glucose homeostasis following intake. The amount of RS in potatoes is dependent upon the type of potato, cooking method, and temperature at which it is consumed. This study examined the influence of consuming either a boiled (BP; ∼6 g RS) or baked then chilled Russet potato (BCP; ∼12 g RS) on postprandial plasma glucose, insulin, and glucose-dependent insulinotropic peptide (GIP). Subjective satiety and 48-hour subsequent food intake were also compared following the intake of each potato. Methods Overweight healthy females consumed 250 g of either BP or BCP on two separate visits with a one-week washout period in this randomized, crossover study. Fasted blood samples were collected upon arrival, and again after potato consumption at 15, 30, 60, and 120-minute intervals for glucose, insulin, and GIP determination. Area under the curve (AUC(0–120)) was calculated for each marker. Subject satiety was obtained from a 100 mm Visual Analogue Scale (VAS) at 15 and 60 minutes after potato intake. Subsequent 48-hour food intake was obtained via diet records following each visit and analyzed using the Nutrient Data System for Research software. Paired t-tests compared each blood collection time point and the AUC(0–120) for glucose, insulin, and GIP, as well as mean subsequent energy and subjective satiety were compared between each potato. An alpha level of 0.05 indicates significance. Results Twenty-five females with a mean BMI of 31.8 ± 7.4 kg/m2 and age of 29.0 ± 5.9 years completed the study. The AUC(0–120) for insulin (P = .011) and GIP (P < .001) were lower following BCP than BP. Plasma insulin was lower at 15 (P = .013) and 30 (P = .039) minutes and GIP was lower at each time interval (P < .05) following BCP intake than BP. Subsequent energy or overall mean subjective satiety did not differ between BCP and BP; however, a lower glycemic index (GI) diet was consumed following BP was observed than BCP (P = .04). Conclusions Compared to BP, BCP resulted in lower AUC(0–120) insulin and AUC(0–120) GIP following consumption. Consuming BP resulted in the intake of a lower GI diet over the following 48-hour period. Potatoes high in RS may be a useful food to modulate insulin and GIP in females who are at risk for developing prediabetes. Funding Sources The Alliance for Potato Research and Education and the University Small Grant Program.