Detoxification is an alternative medicine approach that proponents claim rids the body of "toxins", accumulated harmful substances that are alleged to exert undesirable effects on individual health. Detoxification usually includes one or more of: dieting, fasting, consuming exclusively, or avoiding specific foods (such as fats, carbohydrates, fruits, vegetables, juices, herbs or water), colon cleansing, chelation therapy, or the removal of dental fillings. Body cleansing is not supported by science at this point, with no medical benefits demonstrated, and is based on questionable or disproved scientific claims. The toxins are usually undefined, with no evidence (or inappropriately used testing) for toxic accumulation in the patient.