These little protein-packed gems are full of fiber and water — two ingredients that make you feel fuller faster. Digested more slowly than other high-protein foods such as meat, beans keep your belly satisfied longer. Studies show people who eat legumes are slimmer than those who don't. Beans also stabilize blood sugar levels, which suppresses hunger longer. Add beans such as kidney, black, or pintos to your salads, pasta, soups, and whole grains.