[Hypocaloric nutrition or strict protein intake in the postoperative period]

The purpose of this study was to verify the statements of Blackburn concerning the positive effects of strict nitrogen hypocaloric diets. Three groups of 10 postoperative patients received hypocaloric diets. A carbohydrate diet of 200 grams was given to the first series of patients, a nitrogen diet of 12.4 to the second and finally a carbohydrate-protein diet consisting of 200 grams Sorbitol and 12.4 grams nitrogen to the third. Patients were followed for five days. The existence of post-aggression reactions was determined through measurements of GH, Cortisol, glycemia, insulinemia, fatty acids and ketone bodies. Patients under the strict nitrogen diet presented a less elevated hyperglycemia than the other groups. Insulinemia was also lower with values returning to normal by the second day. This same group showed a significant rise of free fatty acids with ketonemia, an obvious sign of lipolysis. The respiratory quotient, near 0.7, was also indicative of lipolysis. The cumulative nitrogen balance over five days was much less negative than for patients under a strictly carbohydrate diet: the nitrogen balance closest to zero was however obtained for patients under the carbohydrate-protein diet. The combined analysis of the respiratory quotient and the nitrogen balance allowed an evaluation of the respective participation of lipid and carbohydrate nutriments to the energy supply in function of the three types of diet. Lipid participation was of 36% under the carbohydrate diet, 48% under the carbohydrate-protein diet and 84% under the strictly protein diet.