Supplementation with conjugated linoleic acid (CLA) was shown in a 12-month study to help overweight adults decrease body fat mass and increase lean body mass by as much as 9%. The study, published in the June issue of the American Journal of Clinical Nutrition, is the first to establish the efficacy of CLA supplementation in reducing BFM and increasing LBM over an extended time period without changes in exercise or diet.

The double blind, placebo-controlled study randomized 180 men and women, aged 18 to 65, with a body mass index (BMI) of 25 kg/m2 to 30 kg/m2, into three groups receiving capsules containing 4.5 grams per day of CLA-free fatty acid, 4.5 grams per day of CLA-triglycerides, or 4.5 grams per day of olive oil (placebo), respectively. Over the 12-month duration, body weight, BMI and adverse events were assessed every three months; body composition and blood samples were also analyzed regularly.

The Norwegian researchers found a significant decrease in body fat mass in both groups receiving CLA compared to placebo, and the CLA-free fatty acid group had an increase in lean body mass compared to placebo. The study results were not attributable to changes in diet or exercise.

The authors of the study concluded both forms of CLA cause a significant decrease of body fat mass over a one-year period in healthy, overweight adults.

DSIB Dietary Supplement Research Update, June 2004