This will be a parallel randomized, double-blinded, placebo-controlled trial. Sixty-six overweight or obese men and women aged from 18 to 45 years with elevated body fat percentage, who also meet our inclusion and exclusion criteria, will be randomly assigned to: the treatment group, daily supplementation of 3.2 g CLA (Cis-9, trans-11 isomers and trans-10, cis-12 isomers) plus lifestyle counselling weight loss program; or the control group, daily supplementation of sunflower oil. The intervention will include a 3-day run-in phase and 12-week interventional phase. At baseline and the end of the intervention, physical examination including questionnaires, anthropometric measurement, body composition by Dual Energy X-ray Absorptiometry (DXA), biological sample collection will be undertaken. During the invention, regular lifestyle counselling sessions will be delivered, and detailed record will be tracked for all participants to monitor and improve the adherence and safety.
