The nutritional needs of a normal person in his life span --- from conception through infancy, childhood, adolescence, adulthood and old age --- are modified according to the demands of growth and development at different stages of life. Balanced diet at these stages prevents precipitation of deficiency symptoms of any nutrient and protects the subject from any nutritional disorder or disease as well as secondary diseases, mostly infections, caused by lowered resistance due to undernourishment or malnutrition.
The needs of every person at any stage of life are to be modified and deviated from the normal when attacked by illness. Diet therapy can then be considered as a shield, which if effectively used, can protect a person from further attack of the disease and help in restoring, normal health. Thus an understanding of nutrition is the basis of diet therapy. We have studied the normal requirements of a person. Modification of these nutrients can then be considered to be the core of diet therapy.
Use of medication alone is not always sufficient to cure any health disorder unless there is proper nutritional management. On the other hand, in the absence of good and proper nutrition the drug therapy, even though at its best, may become a total failure. On the contrary, it may be possible at least in some instances to avoid or limit the drug therapy with proper nutrition. Because of this awareness the field of therapeutic diets in nutrition has become popular and is gaining wide acceptance in a major cross – section of our society.
Following are some of the cases where therapeutic diets may be required.
- When food consumption is interfered with, as in impaired appetite, gastro – intestinal disease, traumatic neurological disorders interfering with self – feeding, neuropsychiatric disorder, disease of soft or hard oral tissue, disease of soft or hard oral tissue, alcoholism, pregnancy anorexia and vomiting, food allergy, and disease requiring a restricted diet.
- When absorption is interfered with as in the absence of normal digestive secretions, intestinal hyper motility, reduction of effective absorbing surface, impairment intrinsic mechanism of absorption, drugs preventing absorption.
- When nutrition or storage is inferred with as in impaired liver function, neoplasm of gastro – intestinal tract, drug or radiation therapy.
- When the function is impaired or when tissues are destroyed as in achlorhydria in the gastro – intestinal tract, heavy metals and other metabolic antagonists.
- When there is an increase in excretion or loss of nutrients from the body as in lactation, burns, glycosuria albuminuria, acute or chronic blood loss.
- When there is an increase in the nutrient requirements as when physical activity is increased or in period of rapid growth, pregnancy and lactation, hyper - thyroidism and drug therapy.
Diet therapy is the use of food in the treatment of a disease. This is accomplished by changing the patient’s normal diet in order to meet the altered requirements resulting from disease or injury.
Therapeutic diets are normally advised by the doctor alternating the patient in a hospital.