Conjugated linoleic acid reduces body fat in animals, according to a meta-analysis published in the "American Journal of Clinical Nutrition" in May 2007. But the research results from studies using people aren't conclusive. Even those studies that do show an effect usually show only minimal benefits from taking CLA supplements.
Potential Fat Loss
Some research points to a small weight-loss benefit from taking CLA supplements. A study published in the "British Journal of Nutrition" in March 2007 found that people who took 3.4 grams of CLA for six months lost more body fat than those who took a placebo. Women and people who were obese lost more body fat than men or people who were healthy or overweight.
Size of the Effect
Don't expect to take CLA and have the pounds just melt off. The May 2007 "American Journal of Clinical Nutrition" meta-analysis found that people lost about 0.1 pound per week when taking 3.2 grams of CLA per day. This means that if you're trying to lose weight by taking this supplement, it will take 10 weeks to lose just 1 pound.
Area of Weight Loss
Although some studies have pointed to a potential for abdominal fat loss with the use of CLA, this may not be the main area of fat loss with this supplement. In the 2007 "British Journal of Nutrition" study, most of the fat loss came from participants' legs, but their waist-to-hip ratios were also reduced, so some belly fat was lost.
Not all studies show weight-loss benefits from taking CLA. For example, a study published in the "European Journal of Clinical Nutrition" in 2003 found that although CLA supplementation helped increase feelings of fullness, it didn't result in participants eating less or losing any weight. Another study, published in the "American Journal of Clinical Nutrition" in March 2006, found no benefits for either weight loss or weight-loss maintenance after taking 3.4 grams of CLA per day for a year.