Ever since I found this wonderful site I've been guided to eat...and eat...and eat. My plan has always been to not worry about how healthy I'm eating right now (I'm not eating horribly, but not excellent either) and try to fix my health once I've achieved my maintenance weight. My question is: Is this approach at all plausible? How many of the problems that might (and probably will) occur can be reversed? Is there anything that won't change no matter how hard I try?
Health is very important to me, its just that gaining weight is significantly more important. I don't want to get this into a body-type discussion, but lets just say that I'm barely gaining weight as it is. I can eat more. You can always eat more. It just wouldn't be ideal at all, which is why I'd rather not be burdened with worrying about eating healthier (and generally lower calorie) foods.

Can I reverse (potentially) 5-10 years of poor eating with a bit of cardio and a healthy diet, or is this not as easy as I'm hoping it'll be? Will I die in the process? xD

Thanks to everyone that replies.