Anorexia is an eating disorder that affects people' appetite-usually because of emotional problems. This condition is quite common among teenage girls between the ages of 13 and 18, but it canalso be found in boys. Many young people dream of becoming top models. The slim look is usually considered attractive. So, in order to keep their weight down,these young people simply avoid food. Nowadays, to avoid this ploblem, some modeling agencies require a minimum weight of 110 pounds (50 kilograms) for their female models.