The hypothalamus is a tiny part of the brain that manages hunger. It pulls together the signals from the gut, fat cells and the brain. It tells us when we are hungry and when we have had enough to eat.

Hypothalamic obesity (HyOb) is a complicated medical condition. It can happen from the growth of rare brain tumors. It can also happen from other types of injury to the hypothalamus. Craniopharyngioma (krā'nē-ō-fə-rĭn'jē-ō'ma) is one of the tumors that can cause HyOb.

What Happens in Hypothalamic Obesity?

When the hypothalamus is injured, the brain and the gut have a hard time understanding each other’s signals. The brain cannot “hear” the messages from the body fat, trying to tell the brain to turn off hunger. This mix up in the brain leaves the person always feeling hungry. Because the person is hungry, they will eat more and more. The body will store the extra energy from the food as fat. This can cause one to two pounds of weight gain a week.

As more and more weight is gained, the body begins to store fat in places that it usually does not, like muscles, the liver, and in and around other important organs in the belly. This can make it hard for these important organs to work right and it can harm the person’s health.

Hypothalamic Obesity Symptoms

Besides the feeling of non-stop hunger, the person may feel short-tempered or grouchy because the body makes more insulin.

Insulin is a hormone the body makes to help handle food.

Hypothalamic Obesity Treatment

Some medications have been used with some success with hypothalamic obesity.

Gastric bypass surgery has also been found to help with weight loss and managing hunger in people with hypothalamic obesity.

After surgery, the person loses weight. The body makes less insulin. The constant feelings of hunger are under better control.

Weight loss surgery is not the best option for everyone. It is recommended only after all other weight-loss plans have failed.