Dietary manipulations of body fat-reducing potential of conjugated linoleic acid in rats

To study whether the body fat-reducing potential of conjugated linoleic aci d (CLA) could be increased through dietary manipulations, the effects of th e combination of CLA with different proteins, fats, and sesamin were examin ed in rats. Male rats were fed diets containing 1% CLA or linoleic acid (LA ) in combination with different proteins (20% of casein or soybean protein) , fats (7% perilla oil or soybean oil) and 0.2% sesamin (SES) for 3 or 4 we eks. When the dietary fat source was soybean oil, CLA, as compared with LA, significantly reduced weights of epididymal and perirenal adipose tissues, irrespective of the dietary protein sources. However, the highest reducing effect was shown when soybean protein was given as a protein source. SES s timulated the reduction of epididymal and perirenal adipose tissue weights in both protein diets. In contrast, CLA increased the weight of brown adipo se tissue, and SES further increased it in combination with soybean oil but not with perilla oil. No effect of dietary manipulation was observed on se rum leptin and TNF-alpha levels. Thus, the body fat-reducing potential of C LA can be increased by an appropriate combination with food factors that ma y stimulate fatty acid beta -oxidation.