Conjugated linoleic acid (CLA) is a fatty acid often marketed as a weight loss aid. Available in supplement form, CLA is found naturally in dairy products and in beef. Proponents claim that CLA can reduce fat while building muscle, as well as keep cholesterol in check. Despite these claims, research on CLA and weight loss has yielded mixed results so far.
Does CLA Work for Weight Loss?
For a report published in the American Journal of Clinical Nutrition in 2007, researchers reviewed 18 studies on CLA and fat loss in humans. Results revealed that CLA supplements (taken at a dose of 3.2 grams per day) may produce a "modest loss in body fat."
In another review from the same year, scientists analyzed the available research on CLA and obesity. Published in the journal Public Health Nutrition, the review states that CLA has not shown a significant effect on body weight or body composition in humans. What's more, trans-10,cis-12 (a component of many CLA supplements) was found to have a negative impact on blood sugar metabolism and possibly contribute to insulin resistance.
The most recent research on CLA and weight loss includes a 2011 review from the Journal of Obesity. Looking at studies on supplements thought to affect body fat, the review's authors found that CLA (along with chitosan, chia seed, and several other substances) appeared to be effective for weight loss. However, since the supporting research is limited, the authors warn that more research is needed to determine the safety and effectiveness of these supplements.
Should You Use CLA for Weight Loss?
Due to the conflicting evidence for its effectiveness, CLA cannot currently be recommended for weight loss. Furthermore, it's crucial to take caution when using CLA supplements (due to their potentially negative effects on blood sugar and insulin).
If you're looking to lose weight, make sure to follow a healthy diet, exercise regularly, and consider these alternative weight loss solutions. In addition, it's important to consult your physician before using CLA to help promote weight loss.
Egras AM, Hamilton WR, Lenz TL, Monaghan MS. "An evidence-based review of fat modifying supplemental weight loss products." J Obes. 2011;2011. pii: 297315.
Silveira MB, Carraro R, Monereo S, Tébar J. "Conjugated linoleic acid (CLA) and obesity." Public Health Nutr. 2007 Oct;10(10A):1181-6.
Whigham LD, Watras AC, Schoeller DA. "Efficacy of conjugated linoleic acid for reducing fat mass: a meta-analysis in humans." Am J Clin Nutr. 2007 May;85(5):1203-11.