Abstract
1. Nitrogen balance studies on eight uraemic patients on intakes of 45 - 55 mg nitrogen per kg body weight, and an average of 44 - 57 Calories per kg body weight show a tendency to become decreasingly negative with an increasing energy intake. This trend is also shown with a decreasing faecal nitrogen when expressed as a percentage of dietary nitrogen. 2. Net protein utilization is assessed from nitrogen balance data and. it is suggested that this is related to the combined potential of the urea pool size and the energy available, and that the energy intake can be a limiting factor in anabolism. A suggested assessment of the partitioning of the energy supplied is given. 3. Varying proportions of fat to carbohydrate and polysaccharides to mono and disaccharides have been used as the energy source. The results of such variations, over a wide range show no influence on nitrogen balance in these studies. 4. A preponderance of carbohydrate energy appears to be necessary to ensure a constant supply of tricarboxylic acid cycle intermediates. A plentiful and palatable supply of dietary energy is essential, and. long term acceptance of novel foods can present a major problem in the dietary treatment of uraemic patients.