Effect of a viscous fiber bar on postprandial glycemia in subjects with type 2 diabetes

Objective: To compare the effect of an experimental viscous fiber (VF) crispy bar on the postprandial glucose, insulin, and C-peptide response in adult subjects with type 2 diabetes to two commercially available control crispy bars. Design: The study was a randomized, double-blinded, three period, crossover study. Setting: The study was conducted at two sites: Park Nicollet Institute, International Diabetes Center, Minneapolis, MN, and Radiant Research, Inc., Minneapolis, MN. Subjects: A total of 60 adults with type 2 diabetes taking oral antihyperglycemic medication participated in the study. Intervention: After an overnight fast, subjects consumed a test meal containing an equicaloric amount (300 kcal) of an experimental VF crispy bar or one of two commercially available crispy bars at each of three test visits, followed by a four hour meal tolerance test. Subjects also completed gastrointestinal (GI) response records for the 24 hours following each test visit. Results: The VF crispy bars produced significantly lower glucose (p < 0.0001), insulin (p < 0.0001), and C-peptide (p < 0.0001) responses (as measured by positive area under the curve) in subjects with type 2 diabetes, as compared with the two commercially available bars. Intensity (p < 0.05) and frequency (p < 0.05) of flatulence were significantly higher with the VF bar as compared with the 2 commercial bars. While the VF bar produced significant subjective GI tolerance scoring values, the mean value was below 3 on a scale of 0 (no effect) to 10 (most severe effect) for all tested materials. Conclusions: The incorporation of VF into a crispy bar provided a means to improve blood glucose levels by reducing postprandial glucose, insulin, and C-peptide responses in subjects with type 2 diabetes. Though associated with some GI symptoms, VF may have application in improving the postprandial glycemic response in people with diabetes attempting intensive glucose control.