Background. Recently, a new attention has been paid to beneficial effects of high-fat diet on the body weight
reduction and metabolic profile in obese subjects. In this study we compared the effects of two hypocaloric diets with
different proportion of fat on fatty acid composition (FA) in blood and adipose tissue (AT).
Methods and Results. Forty-four obese subjects were submitted to 10 weeks’ low-calorie diet. Subjects were
randomized into low-fat diet (LFD) (20–25 % of energy content) and high-fat diet groups (HFD) (40–45 %). Before
and at the end of the intervention, samples of blood and subcutaneous AT were taken for the analysis of fatty acid
composition. The diet-induced body weight and fat mass reduction were not different between the two diets. Plasma
triacylglycerols (TAG) were reduced during HFD only. Both diets reduced proportion of n-3 polyunsaturated fatty
acids in AT and of saturated fatty acid in blood TAG, with no difference between the diets. HFD induced a higher
increase of monounsaturated fatty acids in blood TAG. No other diet-induced changes were found in proportion of
major classes of fatty acids. In respect to individual fatty acids, the diets induced a number of changes in AT and
blood, the changes, however, not being different between the diets.
Conclusion. Hypocaloric diets induce a number of changes in fatty acid composition in blood and adipose tissue,
with little differences in respect to the proportion of fat in the diet. The results suggest the diet-induced changes in
fatty acid composition are controlled by the calorie deficit of the diet and the proportion of dietary fat plays a minor
obesity, hypocaloric diet, serum lipids, fatty acids, adipose tissue.