Eat fewer calories. In order to lose weight, a person must use up more calories each day than she takes in. That means she will be hungry, but should only eat medium amounts (not to get full). Losing a pound a week is a good way to tell if a plan is working. Save money by drinking tap water and buying uncut veggies, whole wheat bread, and little or no sauces. Small fast-food items are ok (whopper jr. Without mayo).