The answer to a lot of things like this in my basic and uneducated opinion is to eat healthy and exercise. The more you do both those things the more fun they become until you get to the point you miss doing them and couldn't stand junk and no exercise.
The way I see it, is that a lot of people don't stick at these things long enough to get to that point. I've also noticed, many people go from 0 --> 100% and wonder why they can't handle it and think it's going to be like that forever. Slow and steady changes.
Replace one meal a day for something healthy, or just eat an apple every other day to start. Something, anything. When that becomes normal, change another small part until a year down the road you're eating super healthy and you didn't even really know it. Same with exercise.