1.Avoid sugar and refined carbohydrates These foods will not only lead to tooth decay, but also increase the yeast and harmful microorganisms in the gastrointestinal tract. 2.Avoid spicy food The smell of onion, garlic and other spicy food is easy to stay in your mouth after meal. If you eat too much, the smell may stay in your mouth for up to 24 hours, no matter how hard you brush your teeth. This type of food to avoid include onions, garlic and some strong smell of cheese. 3, avoid smoked meat products bologna, pastrami, garlic sausage and other things, they do not instrument have a strong smell, but also not easy to digest, which leads to gas production in the stomach, causing bad breath. If you will participate in social events, you should avoid these foods within the first 24 hours. 4, avoid certain fish Some fish, such as fish used in pizza, or tuna in sandwiches. Both can leave bad breath and ruin people’s good impression of you. 5, less alcohol and not smoking liquor, beer, wine, whiskey and other drinks are to be avoided. Their residues will adhere to the tartar and seep into the digestive system, when you exhale you may exhale alcoholic fumes, giving people a bad feeling of alcohol. Smokers always have a bad smell of tobacco tar in their mouths, to have fresh breath, it is best to quit smoking.