FDA is not God. "According to the FDA's own guidelines, about 400 milligrams of caffeine is the maximum amount a 'healthy adult' should consume in a day (as a reminder, Panera’s large charged lemonade contains 390 milligrams)." The accumulation of caffeine day in and day out brings on health related issues over time. And since it is over time, like future heart attacks, it is not considered serious enough to say that none is the recommendation by God. It is a stimulant that excites the body in a manner that the body is not supposed to experience. "That thy way may be known upon earth, thy saving health among all nations" (Psalms 67:2).