Effect of High Dose Resistant Starch on Human Glycemic Response

This study examined the effect of adding a high dose of resistant starch (RS) in plain muffins on human glycemic response in sedentary and abdominally obese individuals. A total of 8 participants were randomly assigned to two sequences of treatments (AB, BA) using a 2 × 2 randomized cross-over design. The treatment effect was tested with a muffin that contained 75g of digestible carbohydrates and 30g of RS as treatment condition (TRT, B), while the control effect was tested using a 75-g oral glucose solution as a control condition (CON, A). Linear mixed models were used to test the effects of sequence (AB vs. BA), treatment (TRT vs. CON), and time periods on 2-h glucose values and area under the curve (AUC) after adjustment for covariates (i.e., age, sex, and race). The 2-h postprandial glucose AUC was significantly lower in the TRT than the CON (12.5 vs. 15.6 mmol/L•h, P = 0.002). The glucose levels were also significantly lower in the TRT than did the CON at 30 minutes (6.6 vs. 8.3 mmol/L, P = 0.001), 60 minutes (6.6 vs. 8.5 mmol/L, P = 0.004), and 90 minutes (6.3 vs. 8.1 mmol/L, P = 0.003), respectively. The 2-h postprandial insulin AUC was also significantly lower in the TRT than the CON (P < 0.001). Based on the 2-h glucose incremental AUC values, the RS-supplemented muffins’ calculated glycemic index was 48 (glucose = 100). This study suggests that adding 30g of RS supplementation decreased the glycemic index of muffins in sedentary and abdominally obese adults.