Methods: Experimental diets contained 50% kcal of fat, provided by butter (B) or sunflower oil (S); control diet (C) was isocaloric, with 15 kcal of fat per 100 total kcal, provided by soy oil. Diets were otherwise complete in all nutrients and were administered for 40 days.
Results: Group B had higher levels of total cholesterol and triglycerides than C; S serum lipid profile did not differ from C, despite the higher fat content. Regarding serum and thymus FA profile, B showed an increase of saturated fatty acids and lower levels of ω6 and ω3 FA, and S had lower levels of ω3 fatty acids.
Conclusions: The administration of high-fat diets, during 40 days to adult rats, provoked specific variations on serum and thymus fatty acids, as a consequence of differences in FA profile of their lipid sources. These results reflect the impact that eating habits have on health status. It is important to put emphasis not only on the reduction of total fat intake, but also on choosing healthy sources of fat, replacing saturated fatty acids by polyunsaturated and including oils with higher content of ω3 to keep a balanced ω6/ω3 ratio.