A can of monster has the same amount of sugar as a can of coke. You can be not fat with a diet of taco bell as long as you stay within your body's calorie maintenance level. Not fat is not the same as healthy though and the weight you do carry is probably mostly bodyfat.
I've seen people make energy drinks that look like they could power a city. Anything natural is good. Lots of water and music. It calms you down and eventually forces you to leave your computer for when you need to piss. Also I've only had like 4 monsters through out the year. They don't make me feel different or energetic…