The purpose of this clinical trial is to examine the effects of a low and high dose of conjugated linoleic acid supplement on body composition in obese humans. Individuals with a body mass index between 30 and 35kg/m2 are randomized to receive either placebo, 3.2gCLA, or 6.4g CLA daily for twelve weeks. Changes in body composition, weight, and clinical laboratory values are compared between the three groups.

Sixty healthy obese adult volunteers will be enrolled and randomized into either: 1) placebo, 2) 3.2 g CLA, or 3) 6.4 g CLA groups and supplemented for 12 weeks. Body fat mass (BFM) and lean body mass will be determined by DEXA at baseline and twelve weeks during the intervention. In addition, indirect calorimetry will be performed at baseline and twelve weeks to measure changes in energy expenditure. The effect of CLA supplementation on weight, waist and hip measurements, and BMI will also be determined at 12 weeks. Plasma CLA and pill counts will be measured as an indication of compliance. Several blood parameters will be monitored throughout the study, and five random 24-hour recall surveys will be used to monitor dietary intake of CLA-rich foods, energy, micronutrients and antioxidants.

Inclusion Criteria:

• BMI between 30 and 35 kg/m2

Exclusion Criteria:

• history of chronic disease
• food allergies or intolerances
• drug therapy for diagnosed disease or lipid-lowering
• use of weight-lowering medication or diet
• use of tobacco products
• current or planned pregnancy
• use of CLA supplement in previous 3 months
• current substance abuse
• abnormal clinical laboratory values