Protein-energy requirements of boys 12-14 y old determined by using the nitrogen-balance response to a mixed-protein diet.
Short-term nitrogen-balance response to graded intakes of a vegetable mixed-protein diet and to a milk-egg protein diet was tested in eight healthy male children aged 12-14 y. They received 72, 104, 136, and 168 mg N.kg body wt-1.d-1 for 10 d while on the mixed diet, and 160 mg N.kg-1.d-1 on the milk-egg diet. The mean regression equation was nitrogen balance = 0.64 (nitrogen intake)-74, all values are in mg N.kg-1.d-1. Apparent digestibility was 86% and 85% for the mixed and milk-egg diets when the subjects received 168 and 160 mg N.kg-1.d-1, respectively. Mean nitrogen intake for satisfactory nitrogen retention for growth on the mixed diet was 147 mg N.kg-1.d-1; the recommended protein allowance to cover 97.5% of the population, which was derived by using a CV of 12.5%, is 1.15 g protein.kg-1.d-1. We conclude that FAO/WHO/UNU recommendations are adequate, at least for short-term nitrogen retention; long-term studies are needed to evaluate the chronic safety of this protein allowance.
Gattás
V
V
Clinical Nutrition Unit, University of Chile, Santiago.
Barrera
G A
GA
Riumallo
J S
JS
Uauy
R
R
D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D002677:Chile; D004044:Dietary Proteins / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D009584:Nitrogen / Q000378:metabolism*; D009751:Nutritional Requirements; D012959:Socioeconomic Factors; D014675:Vegetables
D004044:Dietary Proteins; D009584:Nitrogen