Energy balance during recovery from malnutrition

This report presents an account of energy balance of young Jamaican children recovering from protein-energy malnutrition (PEM). This was done in three steps. Initially the true gross energy of a formula used in the treatment of PEM was determined by bomb calorimetry. Then its metabolizable energy content was determined in a group of nine children recovering from PEM. In a similar but different group of eight children total daily metabolizable energy intake (EI), average rate of weight gain (g/kg/day) (WG), and total daily energy expenditure (TDEE) were determined. TDEE was determined by indirect calorimetry using a heart rate counter and is based on the relationship of heart rate to oxygen consumption. In this group, the mean EI was 122.5 kcal, WG was 8.4 g, and TDEE was 92 kcal. The difference between EI and TDEE was 30.7 kcal/kg, or 3.3 kcal/g of weight gain. This difference is presumed to be the stored energy in new tissue and corresponds to a proposed new tissue composition of 31% fat and 14% protein. A regression curve comparison of WG versus EI showed that at zero weight gain EI was 85.5 kcal and each additional gain. The difference of 1.0 kcal between total energy cost and stored energy reflects the energy required to deposit new tissue. Gram weight gain required 4.4 kcal. The latter figure is felt to reflect the total energy cost of weight. From three independent measurements, an estimate of maintenance energy requirements was estimated to be about 82 kcal/kg/day.