Ingredients in green tea promote weight loss. Green tea contains caffeine, a stimulant, which helps to boost physical performance and burn fat, and epigallocatechin gallate, which increases the rate of metabolism, according to Authority Nutrition.
The body uses fat by breaking it down and moving it into the bloodstream. Epigallocatechin gallate slows production of an enzyme that collapses norepinephrine, a fat-burning hormone. An increased level of norepinephrine in the bloodstream burns more fat, freeing it for use by the muscles. Studies show that green tea promotes fat metabolism even while a body is at rest. This reaction increases with physical activity, states Authority Nutrition.