Nutritional Status in the Experiment with 105-Day Isolation as the First Phase of the Mars-500 Project

Abstract

In a 105-day experiment simulating crew life in a interplanetary spaceship, shifts in the nutritional status were assessed in six volunteersthat differed in the body weight index, basal metabolic rate, attitude to the proposed diet, physical exercise, and workload. The results of the investigation showed that hard physical work under the conditions of the experiment led to the formation of the nutritional status against the background of more intensive basal metabolism, elevated metabolism of carbohydrates and lipids, and their increased mobilization from fat depot. Food ration, though it was sufficient to sustain health and fairly high calorie, did not fully meet individual taste preferences of some crewmembers and energy needs for physical activities. Under these conditions, heavy workloads required mobilization of lipids from fat depot and reducedthe hepatic detoxification and metabolic capacities. Self-limitation of eating protein-rich desserts led to a relative deficiency of protein intake. These changes in the diet were the reason why four out of six test subjects reduced their basal metabolism and lost body mass. The recovery of metabolism and slowdown of the body weight loss were achieved under these conditions by supplementing meals with digestible proteincontaining products.