Abstract

1. The present study was carried out to estimate precisely, via the nitrogen balance technique,

 requirement  or Nigerians (earlier estimated via the obligatory N method) using graded levels

 intake.

 2. Fifteen medical students of the University of Ibadan who volunteered to participate in the study

 Graded  levels of protein (0-3, 0-45, 0-6 and 0-75 g/kg body-weight per d) derived from foods similar to be consumed by the subjects.

 3. Each subject was given each of the dietary protein levels for a period of 10 d. Subjects were divided

 groups and the feeding pattern followed a criss-cross design with one group starting with the highest level of

 intake (0-75 g) and the second group starting with the lowest level of protein intake (0 3 g). N

 intake during each of the eleven experimental periods was maintained at 0-2 MJ/kg per d. After  

 adaptation period in each experimental period, 24 h urine and faecal samples were collected in marked

 for five consecutive days for N determination.

 4. Mean N balance during consumption of the four protein levels (0-30, 0-43, 0-6 and 0-75 g/kg) t

 (SD 8.07), — 9.90 (SD 6.64), +9.70 (SD 4.15) and +5.13 (SD 4.62) respectively. Using regression analyses

 daily N requirement was estimated at 110.25 mg N/kg body-weight (0.69 g protein/kg body-weight).

 allowances for individual variations to cover 97.5 % or the population adjusted this value to 0-75g

 body-weight.  Net protein utilization for the diet at maintenance level was estimated at 57.5.