Thermic effect of food, exercise, and total energy expenditure in active females

Objectives: Exercise and the thermic effect of food contribute to total energy expenditure and overall maintenance of health. The aim of this study was to determine the interaction between TEF and exercise on TEE based on meal protein content.

Design: A randomized, repeated measures study.

Methods: Ten active females, of normal body weight, participated. Preliminary maximal aerobic capacity (VO₂max) was determined. Three additional testing sessions consisted of performing a 30-min bout of exercise at 60% VO₂max after consumption of a high (45% total kcal) or low (15% total kcal) protein meal, or fasted.

Results: Repeated measures ANOVA indicated a significant main effect for the feeding protocols (α=.05). The high protein meal elicited a 30.39% and 98.15% greater increase in TEF compared to the low protein meal (p=.006) and fasted state (p<.001), respectively. The low protein meal resulted in 94.34% greater TEF compared to fasted (p<.001). Combined with exercise, high protein meal TEF was significantly greater compared to fasted (p=.010) but was not significantly greater than the low protein meal (p=.122). Significant differences were not found between the low protein meals with exercise compared to fasted conditions (p=.094).

Conclusions: Findings of this study provide insight on increased TEE under acute high protein feeding conditions as compared to a low protein meal and fasted state. Combined with exercise, potential for further increases in TEE exists as a result of TEF.