Like so many things we consume in this world there is no clear line to answer this question. It is more about you and your body - how it processes caffeine, are you allergic to it, the quality of coffee beans, how you drink it and of course the even bigger reason, why do you drink it. So, here's what you need to know:

1 // There is a gene and enzyme, both called CYP1A2, and because coffee is metabolized through the liver if you have the two copies of this gene (one from each parent) you are considered a fast metabolizer of caffeine, meaning it will affect you less than someone who has only one or none of this gene.