Caffeine in a single cup of coffee has the potential of accelerating your metabolism by up to fifteen percent. With most people taking two to three cups in a day, this is an incredible option for anyone targeting reduction in metabolism.
However, health experts advise against excessive consumption because it has a reversal effect. It also exposes you to addiction which will affect your rate of metabolism. Other substances that affect metabolism beyond caffeine are chlorogenic acid, theobromine and theophylline. Theophylline and theobromine have stimulant effects while the acid is biologically active and works by slowing down the absorption of carbohydrates.