Apples are packed with fiber (with over 4 grams per medium apple) and water, so your stomach will stay satisfied longer and want less food. Studies out of Brazil have shown that people who eat at least three apples or pears a day lose weight. In one study, groups were given either oat cookies, apples or pears three times a day. The group given oat cookies did not lose weight while those that ate either the apples or the pears lost an average of nearly three pounds over the course of twelve weeks. What's more, the fruit-munching group had lower blood glucose levels.