The best thing to do, assuming you're not having medical issues such as diabetes, is to eat what your stomach tells you within moderation (no binge eating 2 large pizzas in one sitting) and exercise lightly daily.
"Eat less, move more." Hundreds of diet books are worth about as much as a roll of toilet paper... no, wait... toilet paper has a use.
Of course, cutting down on processed sugar and fruit would help considerably, especially if you have a diet of Twinkies and chocolate pies. Berries, nuts are fine but I think of all that as leaves and twigs. I'd rather eat dead birds (chicken) and bologna sandwiches (parts of the pig you don't want to know about.)