ABSTRACT
Objective: The aim of this research was to determine the relationship among protein (PRO) intake, body composition, and muscle strength in overweight and obese firefighters. A secondary objective was to evaluate differences in body composition and muscle strength among overweight and obese firefighters with low (L; < 0.8 g·kg−1), moderate (M; 0.8–1.0 g·kg−1), and high (H; > 1.0 g·kg−1) PRO intake.
Methods: Relative PRO intake [r_PRO] was evaluated from 3-day dietary logs, self-reported by 43 overweight and obese male career firefighters (mean ± standard deviation; age = 37.3 ± 7.2 years; body mass index = 33.2 ± 5.0 kg·m−2; percent body fat [%BF] = 28.9 ± 4.0%). Body composition (fat mass [FM], %BF, lean mass [LM], percent LM [%LM]) and muscle strength (peak torque [PT], relative peak torque [r_PT] of the leg extensors) were measured using dual-energy x-ray absorptiometry and isokinetic dynamometry, respectively.
Results: Greater r_PRO was associated with less FM, %BF, LM (r = −0.498 to −0.363) and greater %LM (r = 0.363), but not muscle strength (p > 0.05). Fat mass (r = −0.373) and %BF (r = −0.369) were associated with lower r_PT; %LM was associated with greater r_PT (r = 0.373). Individuals with L r_PRO had greater FM (mean difference ± standard error: L–H = 10.08 ± 3.18 kg), %BF (L–H = 3.8% ± 1.4%) and lower %LM (L–H = −3.7% ± 1.3%) than those with H r_PRO (p < 0.05) but no significant differences in muscle strength (p > 0.05).
Conclusions: Protein intake > 0.8 g·kg−1 was associated with more favorable body composition in male career firefighters.
Disclosure
EDR is the principle investigator of a service contract with the North Carolina Department of Public Safety. EDR and AESR are also principle investigators for a research contract with Naturex SA.
Acknowlegments
This project was supported in part by a Junior Faculty Award from the University of North Carolina at Chapel Hill and a grant from the National Institutes of Health (DK056350). EDR is the principle investigator of a service contract with the North Carolina Department of Public Safety. EDR and AESR are also principle investigators for a research contract with Naturex SA.