ENERGY AND NUTRIENT INTAKES DURING HIGH-ALTITUDE ACCLIMATIZATION

Information on the food intake of free living individuals during the i nitial stage of an expedition, when the diet is based on fresh and loc ally available foods, is scarce. A weighed dietary survey was carried out by 10 healthy unacclimatized male subjects who walked from an alti tude 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 sca les and recorded in food record books. The mean daily energy intake wa s 10.03 (SE 1.26) MJ. The average body weight loss was 2.07 (SE 0.6) k g and there was no change in percentage body fat calculated from skinf old thickness measurements. The percentage energy from carbohydrates i n 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 av ailability of foods at this time. With the exception of folic acid and vitamin C, the mean daily intakes of B vitamins, iron, and zinc excee ded the UK Dietary Reference Values. However, these values refer to he althy populations but not to those exposed to high altitude when nutri ent requirements may be increased.