The influence of n-3 polyunsaturated fatty acids and very low calorie diet during a short-term weight reducing regimen on weight loss and serum fatty acid composition in severely obese women

Physiol Res. 2006;55(1):63-72. doi: 10.33549/physiolres.930770. Epub 2005 Apr 26.


Polyunsaturated fatty acids of n-3 series (n-3 PUFA) were shown to increase basal fat oxidation in humans. The aim of the study was to compare the effect of n-3 PUFA added to a very low calorie diet (VLCD), with VLCD only during three-week inpatient weight reduction. Twenty severely obese women were randomly assigned to VLCD with n-3 PUFA or with placebo. Fatty acids in serum lipid fractions were quantified by gas chromatography. Differences between the groups were determined using ANOVA. Higher weight (7.55+/-1.77 vs. 6.07+/-2.16 kg, NS), BMI (2.82+/-0.62 vs. 2.22+/-0.74, p<0.05) and hip circumference losses (4.8+/-1.81 vs. 2.5+/-2.51 cm, p<0.05) were found in the n-3 group as compared to the control group. Significantly higher increase in beta-hydroxybutyrate was found in the n-3 group showing higher ketogenesis and possible higher fatty acid oxidation. The increase in beta-hydroxybutyrate significantly correlated with the increase in serum phospholipid arachidonic acid (20:4n-6; r = 0.91, p<0.001). In the n-3 group significantly higher increase was found in n-3 PUFA (eicosapentaenoic acid, 20:5n-3, docosahexaenoic acid, 22:6n-3) in triglycerides and phospholipids. The significant decrease of palmitoleic acid (16:1n-7) and vaccenic acid (18:1n-7) in triglycerides probably reflected lower lipogenesis. A significant negative correlation between BMI change and phospholipid docosahexaenoic acid change was found (r = -0.595, p<0.008). The results suggest that long chain n-3 PUFA enhance weight loss in obese females treated by VLCD. Docosahexaenoate (22:6n-3) seems to be the active component.

Publication types

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

MeSH terms

  • 3-Hydroxybutyric Acid / blood
  • Caloric Restriction
  • Diet, Reducing*
  • Dietary Supplements*
  • Docosahexaenoic Acids / analysis
  • Docosahexaenoic Acids / therapeutic use
  • Eicosapentaenoic Acid / analysis
  • Eicosapentaenoic Acid / therapeutic use
  • Fatty Acids, Monounsaturated / analysis
  • Fatty Acids, Omega-3 / analysis
  • Fatty Acids, Omega-3 / therapeutic use*
  • Female
  • Humans
  • Middle Aged
  • Obesity / blood
  • Obesity / diet therapy*
  • Oleic Acids / analysis
  • Phospholipids / blood
  • Triglycerides / blood
  • Weight Loss*


  • Fatty Acids, Monounsaturated
  • Fatty Acids, Omega-3
  • Oleic Acids
  • Phospholipids
  • Triglycerides
  • palmitoleic acid
  • Docosahexaenoic Acids
  • Eicosapentaenoic Acid
  • 11-octadecenoic acid
  • 3-Hydroxybutyric Acid