Energy drinks...crap, utter crap. It's just the same stuff as a cup of coffee: tons of caffeine. which we all know is addictive (guarana, kola nut, taurine, etc are all fancy words for caffeine) But unlike coffee you also get a ton of sugar and empty calories, which is really setting you up for a nasty blood sugar spike and crash cycle. If you must, at least try to make sure your energy drinks are of the low-sugar variety and keep your caffeine intake under 675 mgs a day. If you do that, you should be fine.