Whey protein sweetened beverages reduce glycemic and appetite responses and food intake in young females

We hypothesized that whey protein (WP) will reduce the blood glucose spike, increase satiety, and reduce subsequent energy intake. The objective of the current study was to investigate WP-glucose mixed drinks relative to glucose or WP alone on glycemic response, appetite and energy intake (EI). In Experiment 1 sweetened beverages of 300-mL solution were given to 12 normal-weight females once a week after an overnight fast at 50 g or 75 g glucose, 25 g WP or 25 g WP with 50 g glucose. In Experiment 2 similar beverages were given to 15 normal-weight and 15 overweight females at 25 g glucose, 25 g WP alone or with 25 g glucose. Blood glucose and appetite were measured simultaneously at 0, 15, 30, 45, 60, 90, 120, 150 and 180 minutes in Experiment 1 and at the same time points but up to 120 minutes in Experiment 2. EI was calculated from a meal served at 180 minutes in Experiment 1. The blood glucose spike and hypoglycemia were reduced after WP and WP supplemented glucose in both normal-weight and overweight subjects resulting in smaller incremental area under the curves compared to the pure glucose (P < .05). EI was reduced after both WP drinks with or without glucose (P < .05). Changes in appetite and blood glucose at 180 minutes and blood glucose area under the curves were associated with EI. In conclusion, WP sweetened beverages attenuated blood glucose and appetite in both normal-weight and overweight females and reduced EI in normal-weight females at a 25 g level.