Academy of Medical Sciences of I.R. Iran Archives of Iranian Medicine 1029-2977 22 5 2019 05 01 The Effect of Conjugated Linoleic Acid Supplementation on Body Composition, Serum Insulin and Leptin in Obese Adults 255 261 EN Fatemeh Esmaeili Shahmirzadi Saeid Ghavamzadeh Tayebeh Zamani Journal Article 2018 04 15 2018 12 23 Background: Studies have reported contradictory findings regarding the effect of a mixture of 2 conjugated linoleic acid (CLA) isomers on body weight and some serum indices. This study aims to investigate the effect of daily supplementation of these 2 isomers on body composition and serum leptin and insulin levels in obese adults. Methods: This randomized, double-blind clinical trial was performed on 54 adults with class I obesity. The subjects were randomly assigned into 2 groups of 27 and were followed for 3 months so that a total of 3000 mg of CLA supplement and placebo were administered in 3 daily doses in the intervention and control groups, respectively. Body composition indices as well as fasting serum levels of insulin and leptin were also measured. The paired t-test was used for evaluating within-group effects from baseline. The independent t-test was used to compare between-group differences for variables with normal distribution. Results: Although body weight and body mass index (BMI) were not significantly decreased during intervention in groups, but the body fat mass (BFM) (P=0.034), body fat percentage (P=0.022) and trunk fat (P=0.027) decreased significantly during intervention with CLA. The fasting plasma sugar (P=0.042) and Homeostatic model assessment for insulin resistance (HOMA/IR) (P=0.044) in the intervention group declined during 12 weeks of intervention. Serum leptin was associated with a significant decrease during the intervention period (P=0.039). Conclusion: CLA supplementation could reduce body fat and serum leptin. Hence, it could be taken into account as a factor for weight loss but not to control or prevent diabetes.