Is CLA a Good Fat Burner?

CLA's effectiveness as a fat-burner is still controversial.
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It sure would be great if you only needed to take a pill to lose weight. That could prove problematic, however, especially if the pill you choose is conjugated linoleic acid -- or CLA. In early scientific studies with animals, CLA looked like it was a great fat-burner and also a potential diabetes treatment. Unfortunately, studies with humans have yielded conflicting results.

What is CLA?

CLA refers to a group of fatty acids related to linoleic acid, a fatty acid that is required by your body to be healthy. Even though similarities exist between these two compound types, CLA is a nonessential fatty acid because of its structural and functional properties. CLA is found in beef, lamb and dairy products such as milk and cheese but not in amounts high enough to burn fat. If that is what you want, you need to take a supplement.

Inconclusive Evidence

A study published in a 2004 issue of “The American Journal of Clinical Nutrition” concluded that insufficient evidence exists to conclude that CLA burns fat in humans. Researchers called for additional studies, especially ones aimed at determining the safety of long-term CLA supplementation. A 2007 article in “Public Health Nutrition” reported possible side effects of CLA on blood lipid levels, blood glucose control and insulin sensitivity. CLA may actually increase the risk of diabetes in some overweight people because their cells could become less resistant to insulin, interfering with normal blood sugar control.

Supporting Evidence

A study of 40 overweight adults found that those who took CLA supplements showed significantly reduced body fat over a six-month period and did not gain weight during the holiday season. Published in a 2007 article in the “International Journal of Obesity,” this study did not find any of the adverse health consequences reported on in other studies. A meta-analysis of research published in a 2007 article in “The American Journal of Clinical Nutrition” concluded that 3.2 grams per day of CLA resulted in modest fat loss. A Chinese study published in a 2012 article in “Nutrition” concluded that 1.7 grams of CLA taken twice daily reduced the body fat of overweight and obese Chinese men by 2 per cent. They also experienced a 0.9-percent reduction in body weight. Study subjects did show higher levels of cholesterol and triglycerides.


CLA appears to be a safe supplement, notes Joe Cannon, M.S., in his book, "Nutritional Supplements What Works...and Why." It is generally well tolerated with only mild gastrointestinal issues such as nausea, gas and diarrhea. These unpleasant side effects generally go away after a couple of weeks. Symptoms may be less intense if you take the supplement with meat or milk.

Typical dosages range between 3 and 5 grams daily, but check for quality and purity when choosing a supplement brand. For advice on choosing the right supplement, consult your health care provider first, especially if you have diabetes or take any over-the-counter or prescription medications. Overweight people with diabetes should not take CLA, as the supplements may impair blood sugar control.

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