Karamanlis, A.Chaikomin, R.Doran, S.Bellon, M.Bartholomeusz, D.Wishart, J.Jones, K.Horowitz, M.Rayner, C.2008-04-142008-04-142007American Journal of Clinical Nutrition, 2007; 86(5):1364-13680002-91651938-3207http://hdl.handle.net/2440/41969© 2007 American Society for Nutrition<h4>Background</h4>Dietary interventions represent a promising therapeutic strategy to optimize postprandial glycemia. The addition of protein to oral glucose has been reported to improve the glycemic profile.<h4>Objective</h4>The aim of the current study was to evaluate the mechanisms by which protein supplementation lowers the blood glucose response to oral glucose.<h4>Design</h4>Nine healthy men were studied on 3 d each in a random order. Subjects consumed 300-mL drinks containing either 50 g glucose (Glucose), 30 g gelatin (Protein), or 50 g glucose with 30 g gelatin (Glucose + Protein) in water labeled with 150 mg [(13)C]acetate. Blood and breath samples were subsequently collected for 3 h to measure blood glucose and plasma insulin, glucagon-like peptide 1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) concentrations and gastric half-emptying time, which was calculated from (13)CO(2) excretion.<h4>Results</h4>The blood glucose response was less after Glucose + Protein than after Glucose (P < 0.005); GIP was lower (P < 0.005), and there were no significant differences in plasma insulin or GLP-1. Protein alone stimulated insulin, GLP-1, and GIP (P < 0.05 for each) without elevating blood glucose. The gastric half-emptying time was greater after Glucose + Protein than after Glucose (P < 0.05) and tended to be greater for Glucose than for Protein (P = 0.06).<h4>Conclusions</h4>In healthy humans, the addition of protein to oral glucose lowers postprandial blood glucose concentrations acutely, predominantly by slowing gastric emptying, although protein also stimulates incretin hormones and non-glucose-dependent insulin release.enHumansInsulinGlucoseBlood GlucoseDietary ProteinsAdministration, OralGastric EmptyingAdultMaleGlucagon-Like Peptide 1IncretinsJournal article002007359610.1093/ajcn/86.5.13640002509365000162-s2.0-3624895226746954Jones, K. [0000-0002-1155-5816]Horowitz, M. [0000-0002-0942-0306]Rayner, C. [0000-0002-5527-256X]