Epidemiological, clinical and metabolic research has shown a strong association between dietary fatty acids intake and cardiovascular disease (CVD) risk factors and clinical events. Saturated fatty acids (SFA) and trans fatty acids (TFA) derived from industrial hydrogenation of oils have been associated with an increased prevalence of CVD. However experimental results on the relationship between physiological pathologic effects and specific functions of individual SFA are often contradictory. Therefore a more detailed exploration of the potential benefit and risks of specific saturated and trans fatty acids is needed in order to update dietary recommendations. In the case of TFAs, the deleterious effect on CVD has been well demonstrated and a maximum accepted level of 1 % of total energy has been agreed internationally. What is currently under discussion is what would be the best alternative to replace them in the diet.