Jinsh

Under nutrition may result from a great variety of causes. A diet that is in adequate in caloric content, but is of good quality in so far as its composition is concerned, leads only to underweight. In most cases, however, a diet deficient in caloric value is also lacking in essential nutrients.

Malnutrition may result not only from deficiencies of the diet but also from (1) faulty digestion of the food; (2) disorders of the liver and pancreas, discussed in Part IV; (3) increased requirements of the body, as in pregnancy, lactation, hyperthyroidism, etc; or  (4) an increased loss of nutrients, as in glycosuria, albuminuria, diarrhea, etc.

The body weight reflects poorly the state of nutrition, since the intake in large amount of calorically rich material, such as carbohydrate or alcohol, may result in actual overweight in the face of malnutrition. The state of hydration of the tissues must also be taken into account, since inanition may be accompanied by dehydration (as in diarrheal diseases) or by over hydration (as in beriberi),. Correction of the diet in an emaciated individual may be followed, accordingly, by a temporary loss of weight due to the excretion of excessive stores of water.

The diagnosis of under nutrition may be suspected from the dietary history. When pronounced, malnutrition is evident from the physical findings as manifested in the body weight, skin, eyes, mouth, nervous system, etc, and by such special laboratory examination as the x-ray of the skeleton and heart, and studies of the composition of the blood. The detection of early stages of deficiency may be difficult, since these are manifested by nonspecific functional disturbances common to many illnesses.