Postprandial effects of resistant starch corn porridges on blood glucose and satiety responses in non-overweight and overweight adults
Background: Diabetes and obesity are major health concerns in the United States. There are several lifestyle factors that contribute to the development of these conditions and diet plays a large role in both etiology and treatment of these diseases. Poor carbohydrate quality and excess caloric intake can contribute to obesity and the development of insulin resistance, eventually progressing into Type 2 diabetes (DM2) and its associated co-morbidities. Resistant starch (RS), a type of dietary fiber, is thought to be a tool for prevention and treatment of obesity and DM2 due to its slow release of glucose post prandially, low energy density, and colonic health benefits from fermentation in the colon.
Methods: Twenty healthy non-overweight/obese weight (n=10; BMI 18.5-24.9 kg/m2) and overweight/obese (n=10; BMI > 25.0 kg/m2) consumed, in random order, 3 breakfast corn porridges providing 25 g starch derived from corn lines varying in levels of resistant starch. The porridges contained 3.1%, 8.4% and 28.9% RS of total starch. Post-prandial blood glucose was measured using a glucometer at baseline, 15, 30, 60 and 120 minutes. Postprandial satiety using a 100 mm Visual Analog Scales (VAS) was measured at baseline, 30, 60, 120, and 180 minutes. Subjects recorded 24 h food intake and gastrointestinal symptoms upon completion of each visit.
Results: There were no differences in post-prandial blood glucose, satiety, or food intake responses between non-overweight/obese and overweight/obese participants with treatments. After data from the 2 weight groups were combined, mean plasma glucose at peak time-point 30 minutes was significantly lower in subjects consuming 28.9% RS treatment compared to the other treatments. Baseline-adjusted plasma glucose AUC was also significantly lower in subjects consuming the 28.9% RS porridge compared to the other porridges. There were no differences in subjective satiety or 24-hour food intake. Minimal gastrointestinal symptoms were experienced in the 24 hours following all 3 test meals.
Conclusions: RS substitution improved acute and peak post-prandial glucose responses, but higher doses of RS (greater than approximately 30% or more of total starch, the maximum provided in our study) may be needed to increase satiety and decrease food-intake over 24 h after ingesting the RS.