Raspberry ketone is the primary aroma compound of red raspberries. This compound regulates adiponectin, a protein used by the body to regulate metabolism. Raspberry ketone causes the fat within your cells to get broken up more effectively, helping your body burn fat faster. The recommended dose is 100mg per day. To get the same benefit from the whole fruit, you'd have to consume 90 pounds of raspberries.
This is a detailed review of Raspberry Ketones, a popular weight loss supplement that has been shown to be effective in animal studies. Learn more here: http://authoritynutrition.com/do-raspberry-ketones-work/