Protein sparing during treatment of obesity: ketogenic versus nonketogenic very low calorie diet

Metabolism. 1992 Apr;41(4):406-14. doi: 10.1016/0026-0495(92)90076-m.

Abstract

Although it is generally agreed that both ketogenic and nonketogenic very low calorie diets promote weight reduction, there is no consensus on a preference of one diet over the other in regard to protein sparing. In the present study, we compared the effects of isocaloric (600 kcal/d) and isonitrogenous (8 g nitrogen/d) ketogenic (low carbohydrate) and nonketogenic diets on parameters of protein and amino acid metabolism, in 16 morbidly obese women maintained on these diets for 4 weeks while confined to a metabolic ward. Cumulative urinary nitrogen excretion (g/4 wk) was significantly (P less than .01) greater (248 +/- 6 v 207 +/- 12, mean +/- SEM, n = 8), and cumulative nitrogen balance significantly (P less than .02) more negative (-50.4 +/- 4.4 v -18.8 +/- 5.7), during treatment with the ketogenic than with the nonketogenic diet. Plasma leucine concentration (mumol/L) was significantly higher (P less than .05) during treatment with the ketogenic than with the nonketogenic diet at day 14 (210 +/- 17 v 150 +/- 8), but not at day 28 (174 +/- 9 v 148 +/- 8). Whole-body rates of leucine oxidation (mmol/h) were significantly higher (P less than .05) during treatment with the ketogenic than with the nonketogenic diet at day 14 (1.29 +/- 0.20 v 0.92 +/- 0.10) and at day 28 (1.00 +/- 0.16 v 0.75 +/- 0.10). Conversely, proteolysis, as measured by leucine turnover rate and urinary excretion of 3-methylhistidine, was not significantly different between the diets.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Clinical Trial
  • Comparative Study
  • Controlled Clinical Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acids / blood
  • Blood Proteins / metabolism
  • Body Mass Index
  • Creatinine / urine
  • Diet, Reducing*
  • Dietary Proteins*
  • Energy Intake
  • Energy Metabolism
  • Female
  • Hormones / blood
  • Humans
  • Ketone Bodies / metabolism
  • Methylhistidines / urine
  • Middle Aged
  • Nitrogen
  • Obesity, Morbid / diet therapy*
  • Obesity, Morbid / metabolism
  • Obesity, Morbid / physiopathology
  • Time Factors
  • Weight Loss

Substances

  • Amino Acids
  • Blood Proteins
  • Dietary Proteins
  • Hormones
  • Ketone Bodies
  • Methylhistidines
  • Creatinine
  • 3-methylhistidine
  • Nitrogen