Feeding Your Himalayan Expedition: Nutritional Signatures and Body Composition Adaptations of Trekkers and Porters

Abstract

High-altitude exposure leads to many physiological challenges, such as weight loss and dehydration. However, little attention has been posed to the role of nutrition and ethnic differences. Aiming to fulfill this gap, five Italian trekkers and seven Nepalese porters, all males, recorded their diet in diaries during a Himalayan expedition (19 days), and the average daily intake of micro and macro-nutrients were calculated. Bioimpedance analysis was performed five times during the trek; muscle ultrasound was performed before and after the expedition, only for the Italians. The Nepalese group consumed a lot of rice and only Italians consumed cheese. Water intake was slightly over 3000 g/d for both groups. Nepalese diet had a higher density of dietary fibre and lower density of riboflavin, vitamins A, K, and B12. Intake of calcium was lower than recommended levels. Body mass index, waist circumference, fat-free mass, and total body water decreased in both groups, whereas resistance (Rz) increased. Italians reactance (Xc) increased at day 9, whereas that of Nepalese occurred at days 5, 9, and 16. The cross-sectional area of the Vastus lateralis was reduced after the expedition. Specific nutritional and food-related risk factors guidance is needed for diverse expedition groups. Loss of muscle mass and balance of fluids both deserve a particular focus as concerns altitude expeditions.

Diet, Supplementation and Nutritional Habits of Climbers in High Mountain Conditions

“…The average energy supply with the diet was 2833 kcal/day, which provided an insufficient supply of energy relative to demand. The results of another study showed that a group of Italians and Nepalese during an expedition to the Himalayas supplied, respectively, 2793 kcal/day and 2775 kcal/day, which was not enough in relation to the demand [28]. The dietary energy supply in our study was similar to the results presented above (Table 2).…”

“…Many studies have been conducted on changes in body composition caused by staying at high altitude [26,27], or approaches to feeding teams of mountaineers in the high mountains [28][29][30]. There is still a lack of precise guidelines on nutrition in high-mountain conditions, focused on the real needs and referring to the preferences of climbers.…”

OxInflammation at High Altitudes: A Proof of Concept from the Himalayas

“…The average daily intake of participants, estimated from food diaries loaded into an ad-hoc web database [ 22 ], included 39 ± 9 g (13 ± 2% of the total energy intake) of PUFAs among other nutrients and 3000 ± 500 g of water. The trekkers suffered the combined stress of physical exercise and hypoxia, as elsewhere reported with a suppression of the hypothalamus-pituitary gonadal axis and altered thyroid metabolic function [ 38 ], a weight loss and a reduction in total body water [ 22 ], while the mood disturbance scores were lower at high altitude [ 39 ].…”

“…First-void urinary samples were immediately frozen at −20 °C and stored until analysis. Daily food, water, MUFA, and PUFA intake were self-recorded by the subjects, on three non-consecutive days during the trek [ 22 ].…”

Fertility Impairment after Trekking at High Altitude: A Proof of Mechanisms on Redox and Metabolic Seminal Changes

“…Therefore, it is reasonable to assume that the reduction we observed was determined, rather than a disruption in the production processes, by a loss of bodily fluid and sodium triggered by augmented diuresis and natriuresis commonly induced at high altitudes [ 52 ]. Indeed, previous results have shown a loss of bodily fluids in the participants of the “Kanchenjunga Exploration and Physiology” project through a series of bioimpedance analyses during the expedition [ 53 ]. The recovery of volume at Follow-up supports this physiological interpretation.…”