An amino acid called leucine — found in foods, dietary supplements, energy bars and other products — may help people burn fat during periods of food restriction, such as climbing at high altitudes, while keeping their muscle tissue intact, researchers have found.
Wayne Askew, Ph.D., and his co-investigator, Stacie Wing-Gaia, Ph.D., who headed the leucine study, explained that the extreme weather conditions, low oxygen levels, treacherous terrain and strenuous exercise during such climbs create a huge nutritional challenge. Climbers often cannot or do not eat enough calories, failing to replenish their bodies with important nutrients. At high altitudes, fat and muscle loss occurs not only when they are climbing, but also at rest.
“We knew that leucine has been shown to help people on very low-calorie, or so-called ”calorie-restricted diets”, stay healthy at sea level,” said Askew. “It”s one of the components, the building blocks, of protein.
“But no one had tested whether leucine would help people stay healthy and strong at high altitudes, so we added leucine to specially prepared food bars that we gave to the climbers.”
In a pilot study of the feasibility of supplementing the diet of climbers with the branch chain amino acid, leucine, scientists studied 10 climbers for 6-8 weeks as they ascended Mt. Everest. They went to base camp and measured expedition members” fat and muscle by using an ultrasound device placed on the skin and analysed the data to see whether climbers who ate the leucine bar retained more muscle than those who ate a bar without leucine.
One finding that was apparent early on in the study was that the food item in which the leucine was delivered was critically important. The Everest climbers had difficulties consuming the three food bars per day that contained the additional leucine.
Askew pointed out that the findings could help people at lower altitudes who want to lose weight while preserving their lean body mass, or who are elderly and don”t eat or exercise enough to maintain their strength.
The study was recently presented at the 242nd National Meeting & Exposition of the American Chemical Society.