VII.12.A. Malnutrition

During fasting the body tries to supply all of the tissues with the necessary energy.

After fasting for 24 hours, the liver glycogen stores are depleted, and glycogen production from proteins (gluconeogenesis) starts to replace them.

After a longer period of fasting, the basal metabolic rate falls significantly (25%). Ketone bodies are formed from fat stores, and the muscle mass starts to decrease.

The nutritional status may be checked by various laboratory tests.

1. The serum albumin level (this shows a protein deficiency).
2. The transferrin level.
3. The vitamin A and D levels, decreased iron, thiamine, folic acid and zinc levels.
4. The creatinine level (this provides information about the muscle mass).

Organ damage may develop as a result of chronic malnutrition.

1. Proteolysis is impaired.
2. The respiration is impaired (the diaphragm contractility decreases).
3. The GFR decreases (the quantity and the quality of secretion deteriorate).
4. Bilirubin release decreases (the liver function is impaired).

a) Clinical characterization of anorexia nervosa

1. During 3 months a 10% loss of the normal body weight occurs.
2. The body weight is less than 90% of the ideal weight calculated from the height.
3. The BMI is less than 18.5 kg/m².

It was long thought that eating disorders were a feature only of white western women.

Although white western women suffer from this disease 10-50 times more often than its incidence is increasing in men and not only in Western countries. 

Populations at enhanced risk:

1. students (mainly at university),
2. groups where slimness is a requirement (e.g. dancers, fashion models, athletes, gymnasts and jockeys),
3. DM patients,
4. homosexual men.

The reasons for the development of malnutrition may be not only psychological, but also biological:

1. Genetics
2. Stabilization point hypothesis
3. Hypothalamus
4. Failure of leptin regulation
5. Failure in glucostatic regulation (insulin, glucagon, etc.)
6. Neurotransmitters
7. Neuropeptides