One study published in the American Journal of Clinical Nutrition in 2004 found that a group of overweight men and women, who took CLA for a year, lost on average, 9% of their body fat without changing their diet or lifestyle.
5
As for the ‘fat burning’ qualities that are widely linked to CLA, animal research has shown that CLA burns fat by increasing the levels of enzymes (lipase) and proteins that are responsible for breaking down fat. Unfortunately, this is yet to be widely proven in humans.6
A randomised control trial was carried out into the impact of 3.2g of CLA on the metabolism of overweight, but otherwise healthy adults.
It revealed those who took the supplement burned fat stores more efficiently and used less protein for energy compared to the placebo group.7
Meanwhile, a separate study explored the impact of 3.76g of CLA on fat burning and energy expenditure for several months.
It concluded that CLA increased the rate of energy expenditure, specifically by increasing the rate at which fat was burnt.8
However, combining CLA with a healthy lifestyle could see even greater results. In 2001, Norwegian scientists followed 20 healthy adults, who exercised for 90 minutes three times a week, for 12 weeks.
Those who took CLA every day lost more body fat than those who only exercised.9 CLA could even aid weight loss while you catch some ZZZs.
Research by the University of Wisconsin-Madison found CLA enhanced fat burning during sleep.10