Interestingly, most of the increase in metabolism is caused by an increase in fat burning ( 13 ). Unfortunately, the effect is less pronounced in those who are obese. One study showed that caffeine increased fat burning by as much as 29% in lean people, while the increase was only about 10% in obese individuals ( 14 ).
What does it mean to be a fast caffeine metabolizer?
Does drinking caffeine faster make it work faster?
Drinking caffeine quickly doesn’t make it work faster. While it might seem like faster consumption will lead to faster absorption, the speed at which a caffeinated beverage is consumed and the temperature of the beverage don’t appear to meaningfully change the rate of absorption in the body.
Does caffeine make you fat?
In the short term, caffeine can boost the metabolic rate and increase fat burning, but after a while people become tolerant to the effects and it stops working. But even if coffee doesn’t make you expend more calories in the long term, there is still a possibility that it blunts appetite and helps you eat less.