Past research has shown that the colorful purple and red pigments found in the skins of grapes, strawberries, and other fruits and vegetables may help to prevent obesity. However, there is new evidence that whole berries may not be as effective in lowering body fat as berry extracts.

In a recent issue of the American Chemical Society's Journal of Agricultural and Food Chemistry, researchers at the University of Arkansas found that anthocyanins, the pigments found in blue/purple/red fruits, were more effective in preventing obesity in mice on a high-fat diet when they were given as a purified extract in drinking water than they were when fed as whole fruits. In fact, eating whole berries may have actually increased obesity!

Without further studies, it's not possible to know what this means for us, except that blueberries and strawberries can't replace a healthy, balanced diet and exercise for long-term weight control.