Persons most commonly affected: All age groups and both sexes.

Organ or part of body involved: Stomach and Liver.

Causes and risk factors: Emotional upset, nervousness, loneliness, boredom, tension, anxiety, bereavement, and depression; Anorexia nervosa; Acute and chronic infections; HIV; Pregnancy (first trimester); Cancer; Hypothyroidism; and Medications and street drugs.

Prevention: Protein and calorie intake can be increased by intake of high-calorie, nutritious snacks or several small meals during the day. Liquid protein drinks may be helpful. Family members should try to supply favorite foods to help stimulate the person's appetite.