Q: i have seem some guys who always eat junk food for the most part(almost daily)but they are always thin.If i do it i gain fat very fast.How do they manage to do it?They dont eat a lot but they eat from outside in a daily base,yet always stay thin.This is so fustrating,isnt it?

A: Half of it is that they don't eat a lot, like you said. If you eat a little, even if it's junk, you're not going to gain much, if any, fat. The second half of it is that not everyone's genetics are the same -- some people gain weight and fat easier than others.

In either case, their 'luck' will only take them so far. Young guys who are skinny and lean and who eat like you described are guaranteed to start growing pot bellies by their mid-to-late 20s and beyond unless they start exercising and eating right. And the older they get the worse it'll get. So by exercising and eating well you're building a huge advantage over them that'll only increase as you get older.