Abstract Background Conjugated linoleic acid (CLA) can prevent fatty acid accumulation induced by a high‐fructose diet and improve lipid metabolism disorders in patients. Objectives We aimed to investigate the effect of CLA on obesity and lipid metabolism and its possible mechanism. Methods Eight‐month‐old male BKS.Cg‐Dock7m +/+ Leprdb/JNju (db/db) mice (n = 12) were fed a CLA mix composed of equivalent c9, t11‐CLA and t10, c12‐CLA for 1 month. The effect of CLA on body weight, water and food intake, and triglyceride (TG) and total cholesterol (TC) levels was investigated. PPARα, PPARγ and CD36 expression was determined by quantitative PCR and western blotting. Additionally, the expression of these three genes was studied in HepG2 cells treated with CLA and linoleic acid. Results CLA treatment notably reduced the dietary and water intake of db/db mice, effectively reduced body weight, and decreased serum TG and TC levels (p