Energy and nutrient intakes during high-altitude acclimatization

Abstract

Information on the food intake of free living individuals during the initial stage of an expedition, when the diet is based on fresh and locally available foods, is scarce. A weighed dietary survey was carried out by 10 healthy unacclimatized male subjects who walked from an altitude of 2430 m to Everest Base Camp (5400 m) in 10 days. All food and fluids consumed during the study period were weighed using dietary scales and recorded in food record books. The mean daily energy intake was 10.03 (SE 1.26) MJ. The average body weight loss was 2.07 (SE 0.6) kg and there was no change in percentage body fat calculated from skinfold thickness measurements. The percentage energy from carbohydrates in the diet was significantly higher (p < 0.05) in the final 3 days (59%, SE 2.0) compared with the first 3 days of the study period (51%, SE 3.6). It is likely that the high carbohydrate intake reflected the availability of foods at this time. With the exception of folic acid and vitamin C, the mean daily intakes of B vitamins, iron, and zinc exceeded the UK Dietary Reference Values. However, these values refer to healthy populations but not to those exposed to high altitude when nutrient requirements may be increased.