Avoid sugary foods. When bacteria in the mouth break down simple sugars, they produce acids that can erode tooth enamel, opening the door to decay. “Sugary drinks, including soft drinks and fruit drinks, pose a special threat because people tend to sip them, raising acid levels over a long period of time,Carbonated drinks may make matters worse, since carbonation also increases acidity.Sticky candies and chocolates are another culprit, because they linger on teeth surfaces.