Sugary snacks taste great, but they aren't so great for your teeth. Foods high in sugars and starches contribute to the production of plaque acids that attack tooth enamel. Eventually, these acids can cause tooth enamel to break down, forming a cavity. If you must eat foods high in sugar or starch, eat them during meals rather than between meals, and avoid any foods that stick to your teeth as these can produce more plaque. To avoid stains, be mindful of tea, coffee, soda and other dark foods and beverages that can discolor your teeth.