I reached my first goal of 145 last summer. I have managed to maintain within 4-5 pounds since then. My secret is: I step on the scale every morning to make sure I am not letting the weight slip up on me. If it looks like I'm gaining, I can refocus on my food and exercise.
I will sometimes have a Slim-Fast shake before dinner and then have only a small portion of the dinner. I do this only if the meal is on the "not so healthy" side. Having the Slim-Fast gets me my nutrition and helps fill me up.
One of my secrets has been to join team challenges and to make challenges for myself. Once I have committed to something, I am likely to stick to it. My favorite is the virtual trip I am on. I ride my stationary bike and log the miles. I'm visiting all of the NASCAR tracks. It makes my ride fun.