11.Constant Snacking
Snacking produces less saliva than a meal, leaving food bits in your teeth for hours longer. Avoid snacking too frequently, and stick to snacks that are low in sugar and starch — for example, carrot sticks.
12.Drinking Coffee
Coffee’s dark color and acidity can cause yellowing of the teeth over time. Fortunately, it’s one of the easiest stains to treat with various whitening methods. Talk to your dentist if you’re concerned about discoloration of your teeth.