Abstract
BACKGROUND: Resistant starches type 4 (RS4) are chemically modified starches that are resistant to digestion by human enzymes. OBJECTIVE: We aimed to test our hypothesis that replacement of standard starch with RS4 in a baked breakfast bar would decrease postprandial glycemic and insulinemic responses in healthy adults. METHODS: In this double-blind, randomized crossover study, 21 healthy adults [10 men; 20-45 y old; BMI (kg/m(2)): 19.3-27.0] consumed a baked breakfast bar containing tapioca-based RS4 (Actistar 75330; Cargill, Inc.) or a macronutrient-matched control bar, delivering 32 g and 4 g of dietary fiber, respectively. Primary outcome was the incremental area under the curve (iAUC(0-120 min)) for postprandial capillary glucose. Other outcomes included postprandial serum insulin iAUC(0-120 min), glucose and insulin maximum concentration (C(max)), and time to C(max) (T(max)). RESULTS: Median glucose iAUC(0-120 min) was 22% lower (P < 0.05) and median insulin iAUC(0-120 min) was 37% lower (P < 0.05) after consumption of the RS4 food compared with the control food. Glucose and insulin C(max) and T(max) were not significantly different (P > 0.05) between foods. CONCLUSION: The results suggest that replacement of standard starch with tapioca-based RS4 is a practical approach for reducing available carbohydrate in products and achieving postprandial blood glucose management. This trial was registered at clinicaltrials.gov as NCT03239288.