Published online by Cambridge University Press: 09 March 2007
1. A study was carried out to determine the effects of varying the level of energy intake on nitrogen balance in preschool children receiving the safe requirement level of protein, determined in an earlier study.
2. Seven preschool children received four energy levels, i.e. 293, 334, 376 and 418kJ/kg body-weight at the safe level of protein intake of 1·75 g/kg body-weight and N balance determined.
3. The N balance decreased with a decrease in energy intake. However, the N balance was positive at all levels of energy intake studied.
4. Results indicated that at a protein intake of 1·75 g/kg body-weight the minimum level of energy intake for a retention of 40 mg N/kg body-weight in these children was found to be 326·2±45·5 (mean ± SD) kJ/kg body-weight. Below this energy intake the safe level of protein intake became inadequate.