Juices are raw foods and they contain plenty of enzymes that really speed up your metabolism. These enzymes are destroyed during cooking and that is the biggest difference between a cooked and a raw meal regarding your metabolism. The plant enzymes join together with your own digestive system enzymes to promote the speed of your metabolism. Cooked foods take longer to digest and therefore tend to be stored in our body as fat. Raw food, and especially fresh juices, are digested very easily. This will lead to a slimmer you in no time.