Sensible diet and increase in exercise. Keep fat to below 3%, cut out large portions of carbs - rice, bread etc - no refined sugar (it's carcinogenic anyway), lots of unprocessed food (no bought sauces etc) , good old fashioned cooking with large portions of veg. Go easy on most fruit - it's full of fructose which is a natural sugar - but 2-3 portions a day should be ok. Make sure any drinks are low calorie and try 1% fat or skimmed milk.
I find 3-4 small meals better than one large one and eat carrot sticks if I want to nibble. Just don't starve yourself, you're more likely to binge eat, and it won't do your digestive system any good.
Good luck!