The effect of different dietary levels of essential fatty acids on body composition of the rat.

Abstract

Three dietary levels of essential fatty acids (EFA) 3.0, 0.75, and 0.07 cal% were studied for their influence on the concentration of lipids, linoleic and arachidonic acids, water, nitrogen, potassium, and ash of the whole body of rats. The animals were sacrificed and examined at 60, 90, and 120 days of age. They were fed the experimental diets and kept under standardized conditions for two generations or more before the actual experiment. The total body concentration of lipids increased and that of water decreased with increasing age independently of the dietary EFA level. In the rats fed 0.75 cal% EFA, the lipid concentration was higher than in those fed 3.0 cal% EFA, while in rats fed 0.07 cal% EFA the lipid concentration was lower than in those fed 0.75 cal% EFA. The concentration of water varied inversely with that of lipids. The differences were most pronounced at the highest age (120 days), and larger in the female rats than in the males. Nitrogen, potassium, and ash did not differ between the groups at any age. The role of EFA for the amount of the adipose tissue is discussed.