Diet Therapy is not a remedy or cure for the sickness or disease but is a measure to make more effective the medical or surgical treatment.

Diet Therapy begins with the normal diet with some changes such as addition of more nutrients and those nutrients which are deficient in the body probably leading to the sickness, and omission of those nutrients which are less important for the body.

Normal Diet may be modified (1) to provide change in consistency as in fluid and soft diets, (2) to change the energy requirements, (3) to wipe out the deficiency of nutrients, if any, in the diet, (4) to increase the intake of dietary fibre and (5) to make the digestion easy.

CLEAR-FLUID DIET: Whenever an acute illness or surgery produces a marked intolerance for food as may be evident by nausea, vomiting, anorexia and diarrhoea, it is advisable to restrict the intake of food. In such cases the diet is made up of clear liquids that leave no residue, and it is non gas forming and non irritating. This diet is entirely inadequate from a nutritional stand point since it is deficient in protein, minerals, vitamins and calories. It should not be continued for more that 24 to 48 hours. The amount of fluid is usually restricted to 30 to 60 ml. per hour.

FULL FLUID DIET: This diet is used following any operation, in acute gastritis, acute infections. In this diet, foods which are liquid or which readily become liquid on reaching the stomach are given. This diet may be made entirely adequate and may be used over an extended time without fear of deficiencies developing, provided it is carefully planned.

SOFT DIET: This is one of the most frequently used routine diets, many hospital patients are placed on this diet until a diagnosis is made. The soft diet is made up of simple, easily digested food and contains no harsh fibre and no rich or highly seasoned food. It is nutritionally adequate when planed on the basis of normal diet. Patients with dental problems are given soft diet. It is often modified further for certain pathologic conditions.

Peptic Ulcer: In this type of sickness, the normal diet should be modified to include skim milk, boiled egg, steamed fish, rice, rice flakes, puffed rice, well cooked cereal, green leafy vegetables, custards etc all in moderation. Simultaneously few of the foods should be excluded and avoided from the normal diet such as strong tea, coffee, cola beverages, gravies, pickles, spices, curries, fried foods, heavy sweets, unripe fruits, raw vegetables (salad) etc.

Obesity: Obesity may increase the incidence of heart attack. Obesity is a physical condition wherein body’s fat percentage is more than 30 percent. Excess body fat puts pressure on heart and its performance. It results in imbalance between the body mass and strength of heart muscles. Deposits of fat in the myocardium decrease the efficiency of heart and also abdominal fat interferes with movements of the diaphragm and free action of the heart. It is necessary to reduce the excess fat through well planned exercise program and diet program. The obese persons should be put in a vegetarian diet. The advantage of a vegetarian diet is that it is low in calories, fat and cholesterol. It is also high in dietary fibre which helps in binding and excretion of cholesterol. Following foods should be excluded from the diet of obese persons – ghee, butter, cream, egg yolk, animal fats, cheese, sweets, fried foods, and excess salt. Diet should be modified to include leafy vegetable, salad, egg whites, skim milk, vegetables, and fruits. Small amounts of food at frequent intervals are preferable to avoid strain on heart.

Hypertension: Hypertension or elevation of the blood pressure above normal is a symptom which accompanies many cardio vascular and renal diseases. A low calorie, low fat, low sodium diet with normal protein intake is advisable.

Typhoid: Typhoid is an infectious disease with an acute fever of short duration. The disease begins in the small intestine and eventually reaches the blood stream. The disease is characterized by a continued and high inflammation of the intestine and formation of intestinal ulcers. At first clear fluid diet is given followed by full fluid and soft diet is suggested. On liquid diets the patient may not meet high calorie and high protein requirements and as such the moment patient shows some improvements, soft diet can be given. Because of the intestinal inflammation, great care must be exercised to eliminate all irritating fibres and spices in the diet. AVOID- butter, ghee, vegetable oils, irritating fibrous foods, chillies and spices, rich pastries, fried foods, heavy puddings and cream soups. INCLUDE:- fruit juices with glucose, coconut water, milk, milkshakes, thin dal, eggs, baked fish, cottage cheese, cereals, steamed vegetable soups etc.

Tuberculosis: Tuberculosis is an infectious disease caused by the bacillus mycobacterium tuberculosis. It affects the lungs most often but may also be localized in other organs, such as the lymph nodes or kidneys. It is often accompanied by wasting of tissues, exhaustion, cough and fever. A high calorie, high protein, high vitamins and minerals, high fluid soft diet is recommended.

Underweight: Being under body weight than the normal is not a sickness of disease but it my lead to any sickness due to less muscles in the body thereby making the body weak. Modified diet should include enough carbohydrates and protein given every three hours. Since digestion may become a problem with modified diet, it is also recommended to do regular physical exercise (preferably weight training).

Jaundice: Jaundice is caused due to damage of liver by Hepatitis A virus. In such case avoid pulses, beans, meat, fish, chicken, egg, soups, ghee, butter, oils, bakery products, dried fruits, nuts, spices, papad, chutney, alcoholic beverages, fried preparations, whole milk, cream etc. Foods that should be included in the diet are cereal, bread, rice, skimmed milk, fruit, fruit juices, sugar, jaggery, honey etc.