| The acute metabolic responses to consuming isocaloric drinks containing either whey protein concentrate (WPC), whey protein hydrolysate (WPH), or carbohydrate placebo (CHO) were examined. In a single-blind, randomized, crossover design, 14 healthy young men consumed each of the treatments and had their resting energy expenditure (REE) and respiratory exchange ratio (RER) assessed by indirect calorimetry over a 3-hr postprandial period. Values were compared to a pretreatment, fasting baseline measurement using repeated-measures ANOVA. WPH and WPC significantly (p < .05) elevated REE versus CHO, and WPC elevated REE greater than WPH at 120 min. WPH significantly (p < .05) lowered RER compared to CHO and WPC at 90 min. Both proteins increased REE versus isocaloric CHO, indicating a higher thermic effect of food. WPH, but not WPC, influenced substrate utilization with a shift favoring lipid metabolism versus CHO, which may help explain previous findings of fat loss with WPH, but not WPC. |
