The hardest part of starting a workout program and keeping the weight off all comes down to one simple thing. Its not nutrition, its not how hard you workout, although these are definitely enormous factors. But the one thing that can make the absolute most difference is all in your head. It's the willpower to push play every day. It's the willpower to get up off the couch and get moving. It's the willpower to say no to the unhealthy habits. It's the willpower to be the absolute best you can be!
In the current program I'm doing, RevAbs, the trainer Brett Hoebel seems to end almost every workout with reminding you that you have to get your head in the game. Sure, you can get up and push play and watch the people on the DVD do their thing, but if you don't get up and do it with them then you obviously didn't have the willpower to make it through. As such, you have to tell yourself every day when you wake up not only that you will eat right and workout that day, but when you will work out and exactly what you will eat. Willpower doesn't just happen, it is your decision to make that difference in your own life that creates the willpower in you to succeed and become the absolute best you can be!
So, write down your goals. Remind yourself of them every day. The more you remind yourself of those goals you want to accomplish, the stronger your willpower will become!