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close this bookProtein-Energy Requirements of Developing Countries: Evaluation of New Data (UNU, 1981, 268 p.)
close this folderProtein-energy requirements-adults
close this folderInterrelationships between effects of protein and energy intakes on nitrogen utilization in adult men
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View the documentEffect of nitrogen intake on nitrogen utilization (1, 2)
View the documentConcluding comment
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Concluding comment

Energy intake has a proportionately greater effect on nitrogen utilization than does nitrogen intake in young men when energy and protein intakes vary around the maintenance level. Recently, Tor al. (7), studying the effect of physical exercise on protein requirements, suggested that not only are energy requirements influenced by the level of protein intake but also protein requirements are affected by energy intake. Clearly, the interaction of protein and energy must be taken into account in defining the dietary requirements for both protein and energy and also in treating persons with proteinenergy malnutrition.

It should be also be emphasized that evaluation of food protein involves many complex factors. These include not only dietary variables, such as the level of protein

TABLE 5. Increment Rate of Body Composition with Increasing Energy and Nitrogen Intakes


Body composition

Body weight

Water Fat N x6.25
Slope for Et (mg/day) 23.9 23.4 5.4 (52.7) 53 7
Slope for N2(mg/day) 10.3 - 4.6 3.3 ( 9.0) 10.0
E/N ratio 2.4 - 5.1 1.6   5.4

E (energy intake) varied with the percentage of the change from weight maintenance of 55.4 kcal/day i 100 per cent) and nitrogen intake was constant at maintenance of 139 mg/day. N (nitrogen intake) varied with the percentage of the change from weight maintenance of 139 mg/day (100 per cent), and E intake was constant at maintenance of 55,4 kcal/day. and energy intake, but also physiological status, i.e., growth, nutritional status, the presence of infections and other diseases, etc.