Protein absorption and energy digestibility at high altitude.

Details

Serval ID
serval:BIB_0E635AFE1A2F
Type
Article: article from journal or magazin.
Collection
Publications
Title
Protein absorption and energy digestibility at high altitude.
Journal
Journal of Applied Physiology
Author(s)
Kayser B., Acheson K., Decombaz J., Fern E., Cerretelli P.
ISSN
8750-7587 (Print)
ISSN-L
0161-7567
Publication state
Published
Issued date
1992
Volume
73
Number
6
Pages
2425-2431
Language
english
Abstract
To test the hypothesis that malabsorption of dietary protein is partly responsible for the weight loss observed during prolonged altitude exposure, six healthy male subjects [31.8 +/- 4.5 (SD) yr] received 15N-labeled soya protein by mouth and [15N]glycine intravenously at 122 and 5,000 m. From the subsequent 4-day total urine and fecal pools, the different fractions of the administered 15N were determined by mass spectrometry. Weight and skinfold thickness were measured at the beginning and end of the altitude exposure. In addition, the overall digestible energy of the diet at altitude was assessed by a 3-day diet control and adiabatic bomb calorimetric assessment of the energy content of the corresponding fecal pool. The average decrease of the subjects' weight during altitude exposure was 3%. Loss of fat mass at altitude estimated from the skinfold measurements was 9%. Protein absorption, calculated as 100--[fecal excretion of 15N after ingestion of 15N soya protein (% of dose given)--fecal excretion of 15N after injection of 15N glycine (% of dose given)], was not significantly impaired at altitude compared with sea level (96 vs. 97%, respectively), and overall digestible energy at altitude, calculated as 100--percent undigested gross energy in the feces, amounted to 96%. It is concluded that, at least up to an altitude of 5,000 m, malabsorption does not play a role in altitude-related weight loss.
Keywords
Adult, Altitude, Body Composition/physiology, Body Weight/physiology, Calorimetry, Dietary Proteins/pharmacokinetics, Energy Metabolism/physiology, Feces/chemistry, Glycine/metabolism, Humans, Intestinal Absorption, Male, Nitrogen/metabolism, Nitrogen/urine, Nitrogen Radioisotopes/diagnostic use
Pubmed
Web of science
Create date
19/09/2013 10:28
Last modification date
20/08/2019 12:35
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