Differential oxidation of individual dietary fatty acids in humans

Am J Clin Nutr. 2000 Oct;72(4):905-11. doi: 10.1093/ajcn/72.4.905.


Background: Dietary fatty acids that are more prone to oxidation than to storage may be less likely to lead to obesity.

Objective: The aim of this study was to determine the effect of chain length, degree of unsaturation, and stereoisomeric effects of unsaturation on the oxidation of individual fatty acids in normal-weight men.

Design: Fatty acid oxidation was examined in men consuming a weight-maintenance diet containing 40% of energy as fat. After consuming the diet for 1 wk, subjects were fed fatty acids labeled with (13)C in the methyl or carboxyl position (10 mg/kg body wt). The fatty acids fed in random order were laurate, palmitate, stearate, oleate, elaidate (the trans isomer of oleate), linoleate, and linolenate blended in a hot liquid meal. Breath samples were collected for the next 9 h and the oxidation of each fatty acid was assessed by examining liberated (13)CO(2) in breath.

Results: Cumulative oxidation over the 9-h test ranged from a high of 41% of the dose for laurate to a low of 13% of the dose for stearate. Of the 18-carbon fatty acids, linolenate was the most highly oxidized and linoleate appeared to be somewhat conserved. (13)C recovery in breath from the methyl-labeled fatty acids was approximately 30% less than that from the carboxyl-labeled fatty acids.

Conclusions: In summary, lauric acid is highly oxidized, whereas the polyunsaturated and monounsaturated fatty acids are fairly well oxidized. Oxidation of the long-chain, saturated fatty acids decreases with increasing carbon number.

Publication types

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

MeSH terms

  • Adult
  • Breath Tests
  • Calorimetry, Indirect
  • Carbon Isotopes
  • Dietary Fats / metabolism*
  • Fatty Acids / chemistry
  • Fatty Acids / metabolism*
  • Humans
  • Lauric Acids / metabolism
  • Linear Models
  • Linoleic Acid / metabolism
  • Male
  • Mass Spectrometry
  • Oleic Acid / metabolism
  • Oleic Acids
  • Oxidation-Reduction
  • Oxygen Consumption*
  • Palmitic Acid / metabolism
  • Pilot Projects
  • Reproducibility of Results
  • Stearic Acids / metabolism
  • alpha-Linolenic Acid / metabolism


  • Carbon Isotopes
  • Dietary Fats
  • Fatty Acids
  • Lauric Acids
  • Oleic Acids
  • Stearic Acids
  • alpha-Linolenic Acid
  • lauric acid
  • Oleic Acid
  • Palmitic Acid
  • elaidic acid
  • stearic acid
  • Linoleic Acid