Raspberry ketone is the primary aroma compound of red raspberries. Costing up to $20k per kg, it is one of the most expensive natural flavor components used in food production. The Food and Drug Administration placed raspberry keytone on generally recognized as safe (GRAS) status in 1965.
Clinical studies have shown that, in high doses, raspberry ketone can prevent increases in body weight and help lose body fat. Recently on the Dr. Oz show, he gave a demonstration on how Raspberry Ketone pills actually make your cells get rid of fat. You would have to eat about 90lbs of fresh raspberries to get the same amount of the Ketone in the pills. These are available online and you need about 100mg at breakfast to maximize effects.