Diet therapy is concerned with the use of foods for therapeutic purpose. It is method of eating prescribed by a physician to improve health. Diet therapy usually involves the modification of an existing dietary lifestyle to promote optimum health. Therapeutic diets are modified for nutrients, texture and food allergies or food intolerances. Diet therapy is a method of eating to improve health for prescribed by a physician. Diet therapy involves the modification of an existing dietary lifestyle for good health. Some common therapeutic diets are clear liquid diet, full liquid diet, high fiber diet, renal diet, pureed diet, food allergy modification etc. It is branch of dietetics related with the use of food for therapeutic purposes. It is ordered to maintain, restore and correct nutritional status, to decrease calorie for weight control, provide extra calorie for weight gain. It also balances amount of carbohydrate, fat and protein for control of diabetes.