Follow an eating plan that is sensible and you can stick to. Prevention has one that is working quite well for me and my husband.
Even if you aren't into losing weight, we all need some activity. Find an exercise regimen or sport you like and do it. I tried beginners yoga and absolutely love it!
And like Carlon Michelle said, you have to have your mind in the game. If you're mind's not in it, you won't be able to resist the siren song of the brownies. Once you're determined, though, you'll look at the fat and calories in those brownies, and say, Hmmm, I could eat one of those or a whole plate of chicken, brown rice, and veggies. I'll still be hungry after the brownie, but not the meal. No brainer! (Most of the time.)
LOL, on the pic! Anyone who can squat on the scale like that probably doesn't need to lose much weight! :D I love it!