All ETDs from UAB

Advisory Committee Chair

Eric P Plasiance

Advisory Committee Members

Dan Benardot

Brenda Bertrand

Paula Chandler-Laney

Document Type


Date of Award


Degree Name by School

Doctor of Philosophy (PhD) School of Health Professions


The current literature indicates that energy balance and protein consumption influence body composition. However, the effects of protein intake, timed protein supplementation, and energy balance on body composition have not yet been fully investigated in collegiate athletes. The purpose of this research was to assess collegiate athletes using hourly food and exercise data to examine how protein timing and energy balance relate to body composition. Aims 1 and 2 focus on collegiate female soccer athletes and further our understanding of the potential roles that protein amount and frequency and hourly energy balance play in optimizing fat mass and fat-free mass. Three-day hourly food and exercise logs were obtained, and Pearson correlations and a one-way ANOVA were used to analyze the data. Both papers use a cross-sectional study design and draw from the same data set. Aim 1 investigated the relationship between protein timing and body composition. Female soccer players who consumed protein with sufficient frequency to supply predicted daily need and while in a state of energy balance > -300 kcal exhibited lower fat mass and greater fat-free mass. Aim 2 examined the association between hourly energy balance and fat mass in the same population. Collegiate women’s soccer athletes who spent less time in energy deficit had lower fat mass. Aim 3 considered collegiate male football athletes and explains the interplay between energy balance and protein supplementation as it relates to body composition. The goal of this randomized, intervention study was to evaluate the effect of timed versus untimed protein supplementation on fat free mass and body fat percent. While the primary intervention did not result in significant changes in body composition, secondary analyses demonstrated that higher daily protein intake at or above the recommended amount and energy balance or surplus at the time of protein supplement consumption were associated with lower body fat percent in male football players. The findings of this dissertation support the thesis that athletes should be in a reasonable state of energy balance when consuming protein. Additional research on optimal protein timing is necessary before specific timing recommendations can be developed.