The impact of whey protein supplementation in older adults on nutrient intakes and satiety over an 11-week exercise intervention
School of Science / School of Medical and Health Sciences
This study aimed to investigate nutritional factors which could counteract the benefits of whey protein (WP) supplementation in older adults whilst performing resistance training (RT). These included food group intakes, nutrient intakes and satiety ratings. This investigation was a sub-study of a larger trial investigating RT and WP supplementation among older adults.
Thirty-six older adults (mean ± SD: BMI 26.2 ± 3.6 kg/m2) consumed a WP beverage containing 30 g WP and 200 mL water three days/week across 11 weeks, immediately following 1-h of RT. A 3-day weighed food record was completed 4-weeks prior to the study, at baseline and at week 11, to examine overall food group and nutrient intakes. At weeks 1–3, 6–8 and 11, a visual analogue scale assessed satiety.
At week 11 compared to baseline, consumption of fruit (p = .039) decreased; milk and milk alternatives increased (p < .001); protein (p = .016) and percentage energy derived from protein (p = .016) increased. Additionally, participants felt hungrier (p = .033) and fullness increased (p = .022) at week 11. Overall, satiety was significantly greater in females than males (p = .014).
Increased milk consumption and dietary protein was an expected benefit of WP supplementation. However, a decline in fruit serves was noted. Future research should further examine longer-term effects of WP on nutritional status in the aging population.