Acid reflux, also known as heartburn, is caused when excess stomach acid moves up into the esophagus and burns away the protective lining. The best way to avoid the burning pain associated with acid reflux is to avoid anything that might cause stomach acid to rise. In many cases, the type of food that is eaten can make a big difference in the stomach's acid production, which can make a difference in the potential for acid reflux. Different people respond to foods in different ways, so it is not possible to list every food that could make acid reflux worse for every person. Some people may be able to eat these foods without any trouble, while others are irritated by foods that are not listed. The best way to find out which foods are the most irritating is to keep a food diary with a list of everything eaten on a daily basis and any corresponding occurrences of acid reflux. In general, however, there are certain types of foods that cause problems for the majority of acid reflux sufferers. Citrus fruits and tomatoes should be avoided as often as possible because of their high acidic content. Raw onions and french fries can also cause acid reflux problems. Fatty red meats are difficult to digest, so the stomach creates excess acid that can lead to a bout of heartburn. Tea, coffee, and liquor are also known to create heartburn problems because of the acids they contain. High-fat snacks like potato chips and sweets that are rich in butter should also be avoided. Sometimes the acid reflux is bothered more by the way the food is prepared than by the actual food itself. Fried foods in general tend to cause acid reflux to become irritated. Rich foods that are prepared using thick creams or butter can also exacerbate heartburn. Acid reflux sufferers should be careful not to eat too much at one time, as well. Overeating can cause the stomach to become too full, which means that it cannot properly digest the food without causing some overflow of stomach acid. Avoiding rich or acidic foods and eating in moderation can help keep acid reflux from returning regularly.