The document discusses three deficiency diseases: Kwashiorkor, Marasmus, and obesity. Kwashiorkor is caused by protein deficiency and results in edema, hair and skin changes, and lethargy. Marasmus is caused by protein-calorie deficiency and causes emaciation, thin limbs, and muscle wasting. Obesity is caused by overeating energy-dense foods and results in excess fat deposition and increased body weight over 20% above normal.