DIFFERENTIAL FATTY-ACID ACCRETION IN HEART, LIVER AND ADIPOSE TISSUESOF RATS FED BEEF TALLOW, FISH-OIL, OLIVE OIL AND SAFFLOWER OILS AT 3 LEVELS OF ENERGY-INTAKE

To examine interactive effects of dietary fatty acid composition and e nergy restriction on tissue fatty acid accretion, mature rats consumed diets containing beef tallow, fish oil, olive oil or safflower oil wi th free access or at 85% or 68% of free access energy intakes. Restric tion was accomplished by adjustment of dietary carbohydrate level. Aft er 10 wk, animals were killed, and the fatty acid compositions of live r, heart and adipose tissues were examined. Compared with animals give n free access to diets, body weight gains were reduced at wk 10 in fis h oil- and olive oil-fed groups consuming 85% (P < 0.01) and in all gr oups consuming 68% (P < 0.005) of free access energy intake. Liver and heart weights were also lower (P < 0.05) in all groups restricted to 68% of free access energy intake. The type of dietary fat and the leve l of energy restriction influenced fatty acid composition in all three tissues at wk 10. In liver tissue, graded energy restriction increase d (P < 0.02) proportions of stearic acid and decreased (P < 0.03) thos e of palmitic acid. In heart tissue, palmitic acid levels decreased (P < 0.01) with energy restriction. In adipose tissue, significant energ y restriction-related changes in fatty acid composition varied with ty pe of fat consumed. These results emphasize the importance of whole-bo dy energy balance in addition to dietary fatty acid supply in utilizat ion of dietary fatty acids for tissue deposition vs. oxidation.