Researchers at the University of Wisconsin-Madison, U.S. studied the effect of conjugated linoleic acid (CLA), a class of fatty acids found in milk and red meat, on overweight individuals. They recruited 80 obese people, half took 3 grams of CLA dietary supplement daily, the other half a placebo. All followed a diet. Weight loss was about the same for both groups-an average of 5 pounds. Those taking CLA reported less fatigue, dizziness and nausea than dieters taking the placebo. Midway through the study some participants in both groups went off the diet and regained some weight, but the groups gained weight differently. People taking a placebo put pounds back on at a ratio of 75% body fat, 25% lean muscle. Those taking CLA regained weight that was 45% body fat, 55% lean muscle. Researchers theorise that CLA may help block fat cells that are in the body from filling up with fat and it may have some effect on skeletal muscle, possibly stimulating muscle growth and fat burning.