I've had bad experiences with Atkins. It was the cause of a nasty kidney stone that put me flat on my back for a good week. The pain was so bad I thought I was gonna die. Also, for some reason, I think it weakens your immune system.
Anyone who is thinking of doing it should read the book first. Most people don't and that's where they get into trouble (you're only supposed to gorge on saturated fats for the first two weeks!).
Anyhoo - you're pretty young to be even thinking about dieting.
How the hell do you expect to work out without carbs?
-WW