Higher‐Protein Intake during Sustained Negative Energy Balance Attenuates Elevations in Resting Metabolic Rate at High Altitude (4300 m)
Abstract
Resting metabolic rate (RMR) increases in unacclimatized lowlanders who ascend from sea level (SL) to high altitude (HA), contributing to negative energy balance and lossof total body mass. Although RMR declines progressively during HA acclimatization, in part due to the loss of metabolically active fat‐free mass(FFM), RMR remains higher than at sea level (SL) for at least the first 3 wk of residence at HA. At SL, consuming a higher‐protein diet during negative energy balance spares FFM during weight loss, which mitigates the decline in RMR that typically accompanies weight loss. While an elevated RMR aids continued weight loss at SL, this effect may be detrimental while trying to maintain weight at HA. This study examined the effects of protein intake on RMR in 17healthy male SL residents (mean ± SD, 23.4 ± 5.6 y, 81.9 ± 13.9 kg)during a 22 d period of negative energy balance at HA. At SL, volunteers were given dietary instruction to consume a weight maintenance diet containing 1.0 g protein/kg/d for 21 d. Volunteers were then transported to HA (4300 m, Pikes Peak, CO) where they lived for 22 d. On arrival at HA, volunteers were randomized to consume a controlled standard protein (1.0 g protein/kg/d, STD) or higher‐protein(2.0 g protein/kg/d, HIGH) diet designed to elicit a 40% energy deficit (30%caloric deficit, 10% increase in physical activity). Prescribed physical activity and diet were closely supervised. Body weight was measured daily anybody composition was assessed by dual‐energy x‐ray absorptiometry at the end of both SL and HA. RMR was measured on day 0 at SL and days 1, 3, 5, 7, 10, 13, and 19 at HA. RMR was 1769 ± 206 kcal/d at SL (no group differences, P>0.05)and increased to 2777 ± 538 kcal/d on day 1 at HA (P0.05), and changes in FFM and fat mass were not associated with RMR (P>0.05). Consuming 2.0 g protein/kg/d during sustained negative energy balance at HA minimizes elevations in RMR. Whether changes in RMR due to higher‐protein intake would result in attenuated weight loss after a more prolonged stay at HA or with a less severe energy deficit requires further research. The opinions or assertions contained herein are the private views of the author(s) and are not to be construed as official or reflecting the views of the Army or the Department of Defense.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 01, 2017
- Source ID
- 10.1096/fasebj.31.1_supplement.841.18
Entities
People
- Allyson Derosier
- Andrew J Young
- Claire E Berryman
- J Philip Karl
- Marques A. Wilson
- Stefan M. Pasiakos
Organizations
- Oak Ridge Institute for Science and Education
- United States Army Medical Research and Development Command
- United States Army Research Institute of Environmental Medicine