Statistical analysis: Data are presented in text, tables and figures as means ± standard error of the mean (SEM) and values of p<0.05 were considered statistically significant. Secretion responses for insulin, GIP, GLP-1, valine, leucine and isoleucine were calculated for each subject as incremental areas under the curve (iAUC). iAUCs calculation allow for different individual baseline values. iAUCs were calculated using the trapezoid model, from 0-240 min for glucose, insulin and BCAA and 0-120 for GLP-1 and GIP. All individual values below the baseline were excluded and each subject in respective study was their own reference. Secretion responses for glucose were calculated as decremental AUC (dAUC) as the response is predominantly negative. All individual values above the baseline were excluded in the case. Data for statistical comparison for iAUC and individual values were tested for normality and for normally distributed data, samples were compared using general linear model ANOVA with Bonferroni's multiple comparison to test the statistical significance of differences between groups. Repeated measures ANOVA test was used to assess time effect for every respective treatment. Mixed model ANOVA was used to assess treatment and time vs treatment effect. Differences between groups were identified using Bonferroni's multiple comparisons tests. GraphPad Prism, release 5.03 (GraphPad software, San Diego) was used to perform all statistical procedures.