This is what is working for me:
To eat: Yogghurt for brekfast, and a piece of fruit for the mid-day snack. Then a good solid meal around 2 or 3 in the afternoon. Something low on fat and oil, and high in vitamins and nutrients. e.g. baked chicken breast in garlic with some steamed vegetables on the side. or perhaps some grilled fish and salad, then for pudding some fruit. In the evening have a plate of salad, and any time you feel the need to snack reach for the fruit. You can allow your self some chocolate, or even a full ice cream sunday, almost on a daily basis even, just avoid things like bread, cereal, or any of the bread-like foods.
Exercise: Take the stairs, leave 10 minutes early and walk, generally be more active in your day to day routine, and find at least 40 minutes a day to work out. I go to the gym, but you don’t have to. You could do 2 sets of 20 minutes at different times of the day. 10–20 situps before and after sleep, things like that.
Finally, avoid sitting around too long during the day. Going to the gym is all well and good, but if you sit on ass all day, going to the gym will just simulate living a normal life. You need to burn the calories of a normal life, plus the ones at the gym/homeworkout.