First, a standing desk. I always get fat when I'm sitting down for too long.
Then, as soon as you wake up in the morning, eat scrambled egg whites, a can of beans, with a splash of olive oil. Take a multivitamin, and a garlic pill. Drink a lot of water.
Then workout, repeating a circuit of exercises for 25 minutes. I do 4-day splits, (out of habit, mostly) so 4 days in a row I'll exercise, and on the 5th, I rest. I just steal circuits from the 'net every two weeks or so. The key is intensity. The more intense you make the workout, the better you'll do.
Here's a sample circuit:
Pullups x 5 | Ab Wheel Rollout x 10 | Pushups x 15 | Squats x 20 | (no rest between circuits)
The rest of the day, I eat as much as I want of meats(yum), vegetables, and legumes, and I drink a lot of water. I pig out when I'm out with friends, which is every once in a while. Opt for liquor instead of beer, though.