Fat and carbohydrate balances during adaptation to a high-fat

Am J Clin Nutr. 2000 Feb;71(2):450-7. doi: 10.1093/ajcn/71.2.450.


Background: Dietary fat contents are highly variable. Failure to compensate for the positive fat balance that occurs during the shift to a high-fat, low-carbohydrate diet by increasing energy expenditure or by decreasing food intake may result in the gain of fat mass.

Objective: The objective of this study was to investigate the time course of fat oxidation during adaptation to an isoenergetic high-fat, low-carbohydrate diet.

Design: After a 5-d control diet, dietary fat was increased from 37% of energy to 50% of energy for 4 d in 6 healthy, young lean men. Respiratory quotient and substrate macronutrient oxidation and balance were measured in a respiratory chamber. Fasting concentrations of insulin, glucose, and triacylglycerol; maximal oxygen consumption (f1.gif" BORDER="0">O(2)max) during treadmill exercise; and free-living energy expenditure were determined. Body fat was measured by dual-energy X-ray absorptiometry and visceral adipose tissue by computerized tomography.

Results: Compared with the baseline diet, the high-fat, low-carbohydrate diet resulted in positive fat and protein balances and a negative carbohydrate balance. Insulin concentration and the postabsorptive respiratory quotient were positively correlated with the fat balance during the high-fat, low-carbohydrate diet, whereas f1.gif" BORDER="0">O(2)max during treadmill exercise was negatively related to fat balance. With use of stepwise regression, f1.gif" BORDER="0">O(2)max was the best predictor of fat balance. There was a negative correlation between fat balance and carbohydrate balance (r(2) = 0.88).

Conclusion: Both baseline insulin concentration and f1.gif" BORDER="0">O(2)max during treadmill exercise predict fat balance during the shift to a high-fat diet under isoenergetic conditions.

Publication types

  • Clinical Trial
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adipose Tissue / diagnostic imaging
  • Adipose Tissue / metabolism
  • Adult
  • Basal Metabolism
  • Body Composition
  • Dietary Carbohydrates / administration & dosage
  • Dietary Fats / administration & dosage*
  • Dietary Fats / metabolism
  • Energy Intake
  • Energy Metabolism
  • Exercise Test
  • Humans
  • Insulin / blood
  • Male
  • Oxidation-Reduction
  • Oxygen Consumption
  • Radiography


  • Dietary Carbohydrates
  • Dietary Fats
  • Insulin