According to a study published in the American Journal of Clinical Nutrition, green tea acts as a metabolic stimulant. Our metabolism determines how quickly we burn calories, and when it is sped up, the rate at which calories are burned also speeds up. And with green tea, this speed doesn't come from caffeine. Instead it comes from a unique concentration of the naturally-occuring chemical catechin.

However, in addition to stimulating the metabolism, green tea can play a further key role in dieting. At the University of Chicago, studies have revealed that green tea can assist in the reduction of appetite. Most likely this is due to the regulatory effects the herb has on our blood sugar. This can be pivotal for an individual who has issues with eating too much.