Journal of the American College of Nutrition, Vol 6, Issue 6 467-474, Copyright © 1987 by American College of Nutrition

JOURNAL ARTICLE

Metabolic effects of a very low calorie diet in obese children and adolescents with special reference to nitrogen balance

K. M. Widhalm and K. F. Zwiauer
Department of Pediatrics, University of Vienna, Medical School, Austria.

Eight obese children and adolescents, mean age (+/- SD) 12.0 +/- 2.5 years, were treated for 3 weeks with a liquid formula very low calorie diet (VLCD), containing 320 kcal/1339 kj (44 g protein, 33 g carbohydrate, 0.9 g fat). Weight loss after 3 weeks was 8.0 +/- 1.8 kg resulting in 15.3 +/- 4.6% reduction of body overweight. During the dietary period no patient complained of hunger and no serious side effects were observed. Four patients achieved positive N-balance during the second week, all but one in the third week. Mean cumulative N-balance after 3 weeks was calculated to be -23.2 +/- 31.6 gN. Great interindividual variances were observed in the rate of N-loss during the course of the study. No significant correlation was found between cumulative N-balance and weight loss or initial body weight. Blood parameters remained unaffected, except for glucose and urea, which decreased slightly from 74.6 +/- 13.6 to 50.4 +/- 20.1 mg/dl and from 14.1 +/- 4.3 to 8.6 +/- 7.4 mg/dl, respectively. Uric acid concentrations increased slightly, three of eight patients had levels higher than 8 mg/dl and therefore were treated with allopurinol. Total serum protein decreased; serum albumin values did not change. The type of VLCD used in this study proved therapeutically useful in achieving rapid weight loss. Compared with VLCD containing 30% less protein and carbohydrate, a marked improvement of N-balance in 3 weeks could be achieved with the VLCD containing 1 g protein/kg IBW/day. This amount of protein seems to be necessary to obtain the nitrogen sparing effect in children and adolescents undergoing weight reduction with VLCDs.