Effects of Dietary Protein Content on IGF-I, Testosterone, and Body Composition during 8 Days of Severe Energy Deficit and Arduous Physical Activity
Abstract
Effects of dietary protein content on IGF-I, testosterone, and body composition during 8 days of severe energy deficit and arduous physical activity. J. Appl Physiol 105: 58-64, 2008. First published May 1, 2008; doi:10.1152/japplphysiol.0005.2008.-Energy restriction coupled with high energy expenditure from arduous work is associated with an altered insulin-like growth factor-I(IGF-I) system and androgens that are coincident with losses of fat-free mass. The aim of this study was to determine the effects of two levels of dietary protein content and its effects on IGF-I, androgens, and losses of fat-free mass accompanying energy deficit. We hypothesized that higher dietary protein content would attenuate the decline of anabolic hormones and, thus, prevent losses of fat-free mass. Thirty-four men [24(SD 0.3) yr, 180.1 (SD 1.1) cm, and 83.0 (SD 1.4) kg] participated in an 8 day military exercise characterized by high energy expenditure (16.5 MJ/day), low energy intake (6.5 MJ/day), and sleep deprivation (4h/24h) and were randomly divided into two dietary groups: 0.9 and 0.5 g/kg dietary protein intake.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2008
- Accession Number
- ADA489378
Entities
People
- Aaron J. Young
- Bradley C. Nindl
- J. A. Alemany
- M. D. Kellogg
- S. J. Montain
- William J. Tharion
Organizations
- United States Army Research Institute of Environmental Medicine