American Journal of Clinical Nutrition, Vol 23, 408-412, Copyright © 1970 by The American Society for Clinical Nutrition, Inc.

Nitrogen-Balance Studies with Children Fed Foods Representing Diets of Low-Income Southern Families

¹ From the Virginia Agricultural Experiment Station

Nitrogen-balance studies were conducted with 15 preadolescent girls fed diets containing 25 or 46 g protein and about 2000 kcal daily. The diets were developed to simulate diets consumed by many low income families in southern United States. Nitrogen retention by subjects consuming 25 g protein daily was lower than expected, the level of retention being judged inadequate in 5 of the 8 subjects fed this diet. Nitrogen retention increased above 0.3 g/day in 4 of these subjects after the addition of fondant supplying 200 or 400 kcal/day. It was necessary to increase the protein intake of one subject in order to bring her nitrogen retention above 0.3 g/day. Three other subjects given 20 g supplemental egg white in period 6 had a similar increase in nitrogen retention. The poor retention by subjects fed the 25 g protein was attributed to the low sulfur amino acid content of the diet.

Adequate nitrogen was retained by all subjects fed 46 g protein/day, although one large subject in this group required supplemental energy to prevent weight loss.