Both diabetes and obesity influence the gene expressions and the activities of the desaturases in liver of rats(18,19), and we therefore wanted to investigate if the liver and muscle contents of FADS1 and FADS2, as well as tissue contents of EPA, were differently affected by CA intake in ZDSD rats and obese but normoglycemic Zucker fa/fa rats. The gene discussed is FADS2; the disease is obesity due to melanocortin 4 receptor deficiency.