PROTEIN REQUIREMENT OF YOUNG-ADULT NIGERIAN FEMALES ON HABITUAL NIGERIAN DIET AT THE USUAL LEVEL OF ENERGY-INTAKE

A short-term N balance study was conducted in twelve healthy female ad ults aged 21-32 years to determine their protein requirement. Four die tary protein levels (0.3, 0.4, 0.5 and 0.6 g protein/kg per d) were us ed. Energy intake of the subjects was kept constant at 0.18 MJ/kg per d. All subjects maintained their normal activity throughout the study period. N excretion was determined from the measurements of N in a tot al collection of urine, faeces, sweat and menstrual fluid for each die tary period. N balance during the four protein levels were -15.15 (SD 5.95), -5.53 (SD 6.71), +6.15 (SD 4.76) and +12.05 (SD 8.63) mg N/kg p er d for 0.3, 0.4, 0.5 and 0.6 g protein/kg per d respectively. The ca lculated average N requirements from regression analysis was 76.0 (SD 3.37) mg N/kg per d (0.48 g protein/kg per d). The estimate of allowan ce for individual variation to cover the 97.5% population was 95 mg N/ kg per d (0.6 g protein/kg per d). The net protein utilization (NPU) o f the diet was 0.55. When compared with a similar study with men, ther e was a significant difference in the protein requirement between sexe s. Thus, the unjustifiable sex difference in the protein allowance rec ommended by the Food and Agriculture Organization/World Health Organiz ation/United Nations University (1985) Expert Consultation group must be reviewed.