There are three types of tea to chose from; black, green, and oolong (white tea) and are derived from the same plant, the Camelliasinesis but, the leaves are processed differently with each type. Green tea is minimally and rapidly processed so the leaves do not undergo fermentation. Oolong is partially fermented, then dried. Lastly, black tea is the most processed and leaves undergo enzymatic oxidation.
So as you can see green tea has the least amount of processing which means it has the most polyphenols responsible for health benefits. These polyphenols include; epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin gallate (ECG), and epicatechin (EC). These are all of which give green tea the reputation of being a booster of caloric expenditure and fat oxidation through the activation of sympathoadrenal system. British researchers found that ECGC in green tea increases fat utilization by 17 percent during 30 minutes of exercise. This also led them to believe that the combo of this and caffeine produces a fat burning effect.
Biochemically the combo of the two work on several enzymes ,whether separately or together, to promote an increase in energy expenditure and fat oxidation. In addition, some studies have found catechins increase fat-metabolizing enzymes. Its mechanism of action is the inhibition of the enzyme Catechol-O-Methyl Transferase (COMT) which degrades norepinephrine a neurotransmitter that is a part of the sympathetic nervous system. Thermogenesis and fat oxidation are largely controlled by the SNS which explains why catechins and caffeine prolong the lipolytic effect.
So if you are looking to burn calories and ramp up fat oxidation look for a combo of caffeine and catechins found naturally in green and oolong teas. Drink up!
Have a Happy Healthy Day,