Exercise is the best way to do it, doesn't have to be a "sport", any cardio would do. De-stresses and tones while burning the fat. Even a stationary bike 30 mins every two days or so works wonders, or you could start with old fashioned walking, and when that gets too easy climb stairs rather than use the elevator.

You should combine it with a healthy diet, add plenty of vegetables, at least half of what you eat should be that.