The effect of work level and dietary intake on sweat nitrogen losses in a hot climate.

I . Nitrogen intakes, and N output in urine, faeces and sweat have been measured in six young Tanzanian men who were accustomed to a hot climate. The measurements were done while the subjects were receiving first a normal and then a low-N diet; and when they were performing moderate physical work, and had undergone a period of acclimatization. 2. When the subjects were acclimatized and working on a normal diet, their sweat output increased, with a fall in its N concentration. Total sweat N loss increased from an average of 0.10 to 0.71 g/d. 3. The effect of the low-N diet was to decrease both the sweat N concentration, and the rate of increase of total N loss in sweat, as sweat volume increased. 4. It is estimated that maximum sweat N losses would not exceed I g/d on an adequate diet, or 0 5 g/d on a low-protein diet. Our results provide no basis for recommending extra protein allowances to cover sweat N losses for workers in tropical climates.