By suddenly eating a lot less you will slow down your metabolism and then you will gain it all back really fast when you start eating normally again- which you will.
Best way is to eat 3 meals a day but make them small and nutritional: eg- small bowl of cereal and a banana for breakfast, a sandwich for lunch or some home made soup, and dinner should have some protein and some carbs. So, something like chicken breast or fish, with salad, veg and a small amount of pasta, rice or potato. Stop when you are full. Don't eat any cake, sweets, crisps, sugar etc. If you are hungry, eat fruit or have some Echinacea tea (or any fruit or herbal tea- green tea is also good). Also step up your exercise- more walking and swimming, or anything that you enjoy.