Effect of a High Resistant Starch Menu on Glycemic Response in Adults With Obesity and Prediabetes: A Non-randomized Pilot Study

OBJECTIVES: The objective of this pilot study was to determine the effect of consuming a 7-day high RS menu on body weight, BMI, and glycemic response in adults with obesity and prediabetes. METHODS: A 7-day high RS menu was prepared at the university food lab. All foods were analyzed for RS content and ensured that the menu provided a weekly average of ∼30 g RS/day. Participants (n = 11) in this non-randomized pilot study retrieved and consumed each RS rich meal and were instructed to avoid consuming additional foods other than non-caloric beverages. Anthropometrics and fasting and postprandial (15, 30, 60, and 120 min) blood were collected to determine changes in weight, BMI, glucose, and insulin at baseline and after 7 days of High RS meal consumption. Descriptive data are presented as mean ± SD. Wilcoxon signed rank tests were used to report mean differences and 95% CI for total area under the curve (tAUC)((0–120 min)) glucose and insulin. RESULTS: Due to the pilot nature of the study significant changes in anthropometrics and glycemic index after consuming high RS meal for 7 days in adults with obesity and prediabetes were not observed. However, a decreasing trend in both weight (mean -1.6 kg; 95% CI −2.6 to −0.7) and BMI (mean −0.5 kg/m2; 95% CI -2.8 to 8) were observed. Fasting glucose was reduced by −3.8% with greater reductions shown at the 30 (−6.7%) and 60 (−4.9%) min postprandial periods. Insulin showed a more drastic decrease after consuming the 7-day high RS menu than glucose. While fasting insulin had the greatest change (−37.3%), postprandial changes also occurred at 30 (−16.7%), 60 (−24.1%), and 120 (−28.4%) min. CONCLUSIONS: A decreasing trend in body weight, BMI, glucose, and insulin are comparable with studies incorporating supplemental RS and demonstrates the effect of RS structurally and functionally on glycemic response. Trials of longer duration that measures additional biomarkers are necessary to observe the mechanistic action of RS naturally supplied through diet on overall metabolic and physiological health. FUNDING SOURCES: Research Enhancement Program, Texas Woman's University.