Effect of low-calorie diets on metabolism of man under hypokinesia

It has been suggested that a low-calorie diet is more adequate than a high-calorie diet for men under hypokinesia (diminished muscular activity). Thus, the aim of this study was to evaluate the effect of a low-calorie diet on the metabolism of twelve physically healthy men aged 19 to 24 years under 90 days of hypokinesia. They were divided into control and experimental groups of men according to the composition and food value of diet: the control group of men received a food-value diet of 2648 kcal/day and the experimental group a diet with energy value of 1900 kcal/day. For the simulation of the hypokinetic effect both groups of men were kept under an average of 500 steps/day. The metabolism of nitrogen, carbohydrates, lipids, minerals, vitamins and energy was determined. Hypokinesia had a considerable effect on metabolism, the intensity of which was related to the composition of the diet received. This applies most emphatically to protein metabolism. The most pronounced changes were observed in the experimental group of men: changes in nitrogen balance were unreliable, free amino acids excretion in urine was diminished and protein assimilation was apparently unchanged. We concluded that the low-calorie diet was more adequate for man under conditions of diminished muscular activity conditions than the high calorie diet.