It is a good tool to help track your caloric/nutritional intake and how you are burning the calories. Not sure how accurate it is but I would guess it is pretty close on burning calories and very close on number of calories in foods. I used it to help motivate me and to keep me on the diet I wanted. Using it and South Beach, I lost 50 lbs in 6 months while increasing lean/muscle mass considerably. Waist went from 44" to 36". Good luck will be yours if you work hard.