Nutritional aspects of high-altitude exposure in women

Abstract

The nutrient intake and urinary excretion characteristics of eight young university women were studied over a 4-day period at low altitude (140 m) and subsequently over a 7-day sojourn on Pikes Peak (4,300 m). High-altitude exposure was associated with a transient decrease in the consumption of protein, carbohydrate, fat, sodium, calcium, phosphorus, vitamin A, riboflavin, thiamin, and niacin and a more sustained decrease in the consumption of potassium and ascorbic acid. In most instances minimal values were observed during the first 3 days of exposure. The carbohydrate fraction of energy intake was increased at the expense of fat during this time period. Individual hypophagic responses appeared to be related to severity of acute mountain sickness. Altitude had no effect on water consumption but did lead to an average body weight loss of 1 kg. Urinary measurements revealed a marked oliguria during the entire sojourn. These measurements also showed the first 3 days to be associated with a net loss of body nitrogen and sodium. During this time period body potassium and phosphorus were conserved, and probably increased. The urea fraction of body potassium and phosphorus were conserved, and probably increased. The urea fraction of total urinary nitrogen was not affected by altitude exposure, nor was the daily excretion of uric acid and creatinine. Ammonia excretion, however, was reduced to 50% of the low-altitude value and remained at this level throughout the sojourn. With a few exceptions, the qualitative characteristics of altitude hypophagia in women were similar to those reported for men. Quantitatively, however, the responses were much more transient in women.

Disturbed eating at high altitude: influence of food preferences, acute mountain sickness and satiation hormones

“…The reduced energy intake at 4559 m confirms previous findings at similar altitudes 388 where both males and females were shown to reduce their energy intake by more 389 than 30% after ascent to 4300 -5100 m [15,21,33,40]. The present study extends 390 these findings by providing a systematic analysis of certain factors that may 391 contribute to the energy intake reducing effect of hypoxia following rapid ascent to 392 16 high altitude.…”

Effect of Altitude on Body Composition during Mountaineering Expeditions: Interrelationships with Changes in Dietary Habits

“…Therefore, our data do not agree with those of Hannon et al [10] who found an increase in carbohydrates intake in 8 young women over a 7-day period stay at 4,300 m, and with those of Rose et al [33] who studied subjects during progressive decompression in a hypobaric chamber and observed a reduc tion in carbohydrates and an increase in fat consumption.…”

“…It has been demonstrated that the weight loss during the mountaineering expedition could be due to dehydration [6,26]; during acclimatization a decrease of intra-and extra cellular water occurs and this may result in a weight change of about 1-2 kg [5,10,17], but as we evaluated the body weight and body composition at the beginning of the study and 7 days after return to sea level, we can exclude that the weight loss could have been caused by water loss. This fact is very important in the analyses of our results because we determined body composition changes by bioelectrical impedance analysis and Fulco et al [8] dem onstrated that it does not work in the determi nation of changes of fat-free mass at altitude for the interference of water loss.…”

“…Hannon et al [10] demonstrated that sub jects allowed access to any quality of food at high altitude spontaneously increased their carbohydrate consumption. Although a vege tarian diet may be adequate for sedentary people [34], it is unknown if it is adequate during physical performance.…”

Women at Altitude: Effect of Menstrual-Cycle Phase on Acute Mountain Sickness During Deployment to High Altitude Terrain

“…On the basis a query of experienced practitioners in Peru, Fitzmaurice, (1920) suggested that women suffered less AMS then men, but suggested that they did so partially because women lead a less "strenuous life" than males and were more "abstemious in their habits." Acute mountain sickness symptoms measured in eight young women living on the summit of Pikes Peak for 10 weeks, when compared to AMS symptoms in males on Pikes Peak in separate studies, suggested that women possibly are less susceptible to AMS (Hannon, et al, 1976;Harris, 1966). Likewise, Krämar and colleagues (1983) felt that the AMS they observed in seven women climbers on Ana Purna in the Himalayan mountains was less severe than that reported in 12 soldiers on Pikes Peak in Colorado (Kobrick and Sampson, 1979).…”