Lifestyle interventions such as diet-induced weight reduction and exercise are very important in the treatment of obese patients with type 2 diabetes mellitus. Recently, we reported that a 16-week very low calorie diet (VLCD) in obese patients with type 2 diabetes mellitus significantly decreased plasma total cholesterol and TG levels and markedly reduced hepatic TG content (11), but the potential beneficial effect of a VLCD on plasma CETP and HDL levels has not been studied. Therefore, using plasma samples from that study (11), we investigated whether prolonged caloric restriction reduces CETP concentration and thereby increases HDL levels in obese patients with type 2 diabetes mellitus.