Diabetes-specific complete smoothie formulas improve postprandial glycemic response in obese type 2 diabetic individuals: A randomized crossover trial

Abstract

Abstract Background High-protein, low-carbohydrate enteral formulas (EN) can improve glycemic control in individuals for individuals with type 2 diabetes (T2DM) in ambulatory care. This study aimed to compare newly developed diabetes-specific complete smoothie formulas with a standard diabetes-specific nutritional formula (DSNF) regarding their effects on glucose homeostasis, insulin levels, and lipid metabolism in obese T2DM patients. Methods We conducted a randomized, double-blind, crossover study with 41 obese T2DM participants. Two smoothie formulas were developed from locally available Thai products as experimental products: soy-based smoothie drinks (regular smoothie drink; SM, smoothie with modified carbohydrate content; SMMC) containing high protein and low disaccharides (28-39% carbohydrate, 24-28% protein and 37-44% fat). We compared them to the standard DSNF, Glucerna, with its typical composition (38% carbohydrate, 18% protein, and 33% fat). Glycemic and insulin responses were assessed after participants consumed 300 kilocalories of each formulation, randomly on three separate days with a 7-day gap between. Postprandial effects on glucose, insulin, non-esterified fatty acids (NEFA), triglycerides (TG), C-peptide, and glucagon were measured at baseline and at 30, 60, 90, 120, 180, and 240 minutes. Results SMMC resulted in significantly lower glucose area under the curve (AUC0-240) compared to Glucerna and SM (P<0.05 for both). Insulin AUC0-240 after SMMC was significantly lower than after SM and Glucerna (P<0.05). During the diets, the suppression of NEFA was more augmented on SM, resulting in a less total AUC0-240 of NEFA compared to the SMMC diet (P<0.05). C-peptide AUC0-240 after SMMC was significantly lower than after Glucerna (P<0.001). Conversely, glucagon AUC0-240 after SMMC was significantly higher than after SM and Glucerna (P<0.05). Conclusions These results demonstrated that SMMC was the better insulin-sensitive formula among the three formulas of the same caloric level. This effect may be achieved by either through increased insulin secretion or direct reduction in glucose absorption. The positive effects are likely related to their unique composition of carbohydrates, amino acids, and fats from natural ingredients in the smoothies. These smoothies may be a promising functional food for the management and supplementation for diabetes and obesity.