No evidence of enhanced satiety following whey protein- or sucrose-enriched water beverages: a dose response trial in overweight women.

BACKGROUND/OBJECTIVES: To compare the effect of low-dose whey protein-enriched and sucrose-enriched water beverages on postprandial satiety and energy intake.

SUBJECTS/METHODS: Sixty overweight and obese women were given water-based protein and carbohydrate (CHO) beverages or placebo on six different occasions in a double-blind, randomised cross-over study. The beverages were 2 (178 kJ) and 4% (348 kJ) protein-enriched water (Clear Protein8855), 2 (157 kJ), 4 (314 kJ) and 10% (785 kJ) sucrose-enriched water, and a sweetened water control. Beverages were matched for volume, colour, flavour and sweetness. A standardised evening meal was provided before each study day and a standardised breakfast upon arrival at the clinic at 0900 hours. The beverage preload was given midmorning at 1100 hours, and an ad libitum outcome lunch meal at 1300 hours. Subjective appetitive responses were recorded through the day until 1500 hours using visual analogue scales.

RESULTS: Fifty-five participants completed all six beverage conditions. Neither protein nor sucrose preloads decreased any of hunger, fullness, thoughts of food or satisfaction when compared with the sweetened water control beverage (all, P>0.05). There was also no significant effect on ad libitum energy or macronutrient intake at the outcome meal (P>0.05), with no compensation for the energy consumed within the preload beverages.

CONCLUSIONS: There was no evidence of increased postprandial satiety or compensation for energy content at an outcome lunch meal when a water beverage was supplemented with up to 4% (w/w) whey protein or 10% (w/w) sucrose, in a group of overweight but unrestrained young and middle-aged women.