Time of consumption, but not body weight, affects food intake responses to whey protein and glucose in normal weight and overweight/obese children

The role of dietary protein in regulating energy balance has received little examination in children. In normal weight and obese boys, 50 g of glucose reduced food intake (FI) 30 min later, but 50 g of whey protein reduced FI only in normal weight boys (Bellissimo et al 2008, IJO). Therefore, we examined the effect of whey protein and glucose given on a body weight (BW) basis on appetite and FI 30 and 60 min later in 9–14 y old normal weight (10–80th percentile) and overweight/obese (> 85th percentile) children. Fifteen normal weight and 19 overweight/obese children received in random order three equally sweetened drinks containing sucralose, glucose or whey (0.75 g/kg BW) in 250 mL of water 2 h after a standard breakfast. FI at an ad libitum pizza meal was measured after each treatment and time. Appetite was measured throughout the course of the study. BW had no effect on FI following treatments (p = 0.34). Furthermore, across all subjects BW did not correlate with suppression in FI after treatments (r = −0.21, p = 0.23). At 30 min, both glucose and whey reduced FI similarly (~20%, p < 0.001). At 60 min whey, but not glucose, reduced FI by ~22% (p < 0.001). Appetite was not affected by drink or BW, but increased with time to the meal (p < 0.001). We conclude that whey protein and glucose, when consumed on a BW basis, produces similar physiological effects in normal weight and overweight/obese children, but the effect of protein has a longer duration. Grant Funding Source : Canadian Institutes of Health Research (CIHR)