Grubic TJ, Sowinski R, Dalton R, Collins PB, Reyes AG, Favot CJ, Rasmussen C, Greenwood M, Murano PS, Earnest CP and Kreider RB*. Austin J Nutri Food Sci. 2018; 6(1): 1099.
Abstract
This study examined the glucose and insulin response of ingesting a novel protein bar using a plant fiber (isomalto-oligosaccharides, IMO) as the carbohydrate source. In a randomized and crossover manner, 20 healthy men and women (Study 1) donated fasting blood samples prior to ingesting a Food Bar (FB) containing 20 g of a whey protein blend, 25 g of carbohydrate (13 g IMO, 4 g sugar, 8 g fiber), and 7 g of fat (1.5g saturated) or 25 g of dextrose (PLA). The experiment was repeated 7 to 10 days later while ingesting the alternative treatment. In study 2, 10 fasted individuals participated in the same experiment while ingesting 2 FB’s or 50 g of dextrose. Blood samples were taken at 10, 20, 30, 60, 90, and 120min post-ingestion while subjective ratings related to appetite and hypoglycemia were obtained at 0, 60 and 120 min. Data were analyzed by general linear model statistics and are presented as mean [95% CI] changes from baseline. Results revealed that the glycemic response to ingestion of the FB was significantly lower during the first 60 min following ingestion in comparison to the dextrose PLA. The glucose integrated AUC (iAUC) change from baseline was significantly lower with FB ingestion (Study 1 FB 60 [CI 48, 71], PLA 160 [134, 186], p<0.001; Study 2 FB 65 [49,82], PLA 209 [170, 244] mmol-h/L, p<0.001) while no differences were observed between treatments in insulin iAUC responses. In comparison to the dextrose standard, the FB had an iAUC derived glycemic index (GI) of 34 [CI 23, 46] and a Glycemic Load (GL) of 8.5 [CI 5.6, 11.6]. Participants also reported significantly less subjective ratings of appetite and hunger and greater satisfaction from food and feeling of fullness in both studies. No significant differences over time or between treatments were observed in ratings of symptoms of hypoglycemia. Results indicate that ingestion of a whey protein bar using IMO as the source of carbohydrate elicited a low glycemic response in comparison to a reference carbohydrate in healthy individuals. Thus, this FB may serve as a low glycemic food option for individuals on a low glycemic diet and/or athletes interested in optimizing nutrient availability around exercise.
Keywords: Energy bars; Glycemic index; Glycemic load; Glycemic response to food