An epidemiological study comparing overweight to normal weight people showed that normal weight people eat more whole milk products. Perhaps overweight people eat more low fat food but still eat more food. Conjugated linoleic acid (CLA), however, which is found in cow milk and meat in higher concentrations when they are grass fed, may be a factor that speeds up calorie burning. CLA may also have a cancer preventing effect, decrease abdominal fat, enhance muscle growth, and improve insulin sensitivity.