Conjugated linoleic acid (CLA) is a stimulant-free fat burner. The American Chemical Society, the International Journal of Obesity, the Journal of Nutrition, and the Lipids Journal have all published studies showing that CLA diminished body fat and promoted efficient metabolic function.
CLA in its supplement form is derived from safflower oil and is related to the omega-6 essential fatty acids. Although CLA occurs naturally in meat and dairy products, amounts have decreased significantly as commercial producers have switched to a grain-based feedlot diet from a grass-based pastureland diet. This reduction in CLA may be a contributing factor to obesity in the U.S.
During a 14-week study, Swedish researchers at Uppsala University studied 53 overweight men and women aged 23 to 63. At the beginning of the study, there were no statistical health differences among the participants. During the initial two weeks, all subjects took an olive oil capsule placebo. For the remaining 12 weeks, one group was given 4.2 grams of CLA per day, while the others continued to take olive oil capsules. Participants did not change their diets or alter their physical activity regimens, and did not use other supplements. At the conclusion of the study, those who had taken CLA experienced an average 3.8% reduction in body fat.
Another double-blind, randomized, placebo-controlled study published in the International Journal of Obesity concluded that using 4.2 grams of CLA per day reduced abdominal fat among men who were classified as abdominally obese, a condition commonly referred to as "middle-age spread." Participants lost an average of one inch from their waistlines in a four-week period.
Early results from a two-year trial on the long term effects of CLA have shown that one year of supplementation with 3.4 grams of CLA per day reduced body fat by 9% and increased lean muscle by 2%. More positive study findings are expected on this promising natural dietary ingredient.