In my opinion it's very easy to diet and lose weight. All you need to do is fill your stomach with something that will take the place of calorific food before you start eating and that will cut down the amount that you are going to eat.
That something is water. Simply drink a pint or two or three (depending on how big you and your stomach are) of water immediately before you eat. The water will be sitting in your stomach and make you feel full after a regular meal instead of an over-sized one.
You can apply this trick to anytime you feel hungry and don't want to eat. Drink a pint of water and then eat an apple (or a turkey).