[Effect of protein and energy intake on nitrogen metabolism of undernourished patients on continuous enteral nutrition].

Nitrogen balance, energy balance and respiratory quotient were measured in 18 undernourished patients fed with continuous enteral nutrition in order to assess the effects of: a) various levels of protein and energy intakes with a fixed diet composition; b) energy/nitrogen ratio; c) proportions of carbohydrates in energy intake. The results were the following: 1) With energy intakes from 4,880 to 8,360 kJ/m2/day (protein: 18 p. 100) nitrogen balance and net protein absorption were significantly correlated with nitrogen intake (respectively P less than 0.01 and P less than 0.001). 2) Nitrogen balance was not significantly different whether the patient received normo (energy/nitrogen = 476 kJ/g) or hypernutrition ( energy /nitrogen = 1,056 kJ/g). 3) Nitrogen balance was not different in 6 patients receiving the same energy and nitrogen intakes but 80 or 55 p. 100 carbohydrates; high carbohydrates diet induced lipid synthesis. These results confirm the value of continuous enteral nutrition to positive nitrogen balance in undernourished patients. Except when energy expenditure level is very high they do not support a policy of routinely use hypernutrition with high carbohydrates diet.