Thursday, August 5, 2010

No Effect of Type of Dietary Fatty Acids on Fatty Acid Oxidation

Oelic Acid: A mono-unsaturated fatty acid
that is abundent in olive oil (HMBD v2.5)
You may have read quite often that among the benefits of a diet high in "healthy" mono-unsaturated fats is an increase in overall fatty acid oxidation, which in turn facilitates weight loss and has beneficial effects on blood lipids. A study by Copper et.al. (Cooper. 2010) that was published online on July 22, 2010, does yet refute this claim. As the scientists, who investigated the effect of a high-fat diet in 80 exercised (SE=saturated, UE=unsaturated fats) and sedentary healthy (SS=saturated fats, US=unsaturated fats) men state:
Change from day 1 to day 5 showed both exercise treatments increased fat oxidation (SE = 76±30g, p=0.001 and UE = 118±31g, p<0.001) while neither sedentary condition changed fat oxidation (SS = -10±33g, ns and US = 41±14g, p=0.07). No differences for dietary FA composition were found.
In view of the results of a study published only a few weeks ago (Strik. 2010), which found "no evidence of a difference in post-ingestion satiety between high fat meals which differed in saturation profile in this group of lean, healthy men," (Strik. 2010) the purported benefits of poly- an mono-unsaturated fats on a calorie restricted diet is about to joint the overcrowded ranks of popular dieting myths.

Only exercise, but not changes in the composition of dietary fats reliable increase the rate of fat oxidation. Exercise, as the scientists explicitly state, is thus the best way to "achieving fat balance" especially on a high fat diet.