This document discusses various nutritional disorders including obesity, kwashiorkor, marasmus, anorexia nervosa, and bulimia nervosa. It notes that kwashiorkor is a childhood protein-energy deficiency characterized by edema, while marasmus is caused by overall lack of calories seen as "skin and bone." Obesity results from calorie intake exceeding utilization and is measured by body mass index. The body regulates energy balance through hormones like leptin from fat cells and ghrelin from the stomach.