Hypothalamic obesity is abnormal weight gain and obesity that is caused by damage to the hypothalamus. The hypothalamus is the part of your brain that serves as your brain’s control center for hunger, satiety (feeling full), and energy balance.

People living with hypothalamic obesity may feel hungry all the time, even if they’ve just eaten. They may also have a difficult time losing weight, even with diet and exercise. This article will review signs of hypothalamic obesity, common causes, and potential treatment options.

What Is Hypothalamic Obesity?

Hypothalamic obesity is a type of obesity caused by damage to the hypothalamus, a small but important region at the base of your brain. In order to understand hypothalamic obesity, we need to learn more about what the hypothalamus does.

The main role of the hypothalamus is to maintain a stable and balanced state in your body, called homeostasis. The hypothalamus gathers information about your body through hormones (chemical messengers) and nerve signals from around the body. After processing these signals, the hypothalamus responds by influencing the nervous and endocrine (hormone) systems to keep the body in balance.

The hypothalamus helps regulate several body functions, including:

• Hunger
• Satiety
• Thirst
• Metabolism (how the body uses energy)
• Body temperature
• Mood
• Sleep

Damage or injury to the hypothalamus can lead to weight gain and other health problems by disrupting the brain’s ability to maintain this careful balance.

What Causes Hypothalamic Obesity?

The main cause of hypothalamic obesity is damage to the hypothalamus due to tumors, brain injury, or a genetic condition.

Brain Tumors

A brain tumor is an abnormal growth of brain cells. If a brain tumor develops in or near the hypothalamus, it can cause damage that affects the ability to regulate your appetite and metabolism. In some cases, the brain tumor itself can cause hypothalamic obesity. However, it’s more common to develop hypothalamic obesity as a side effect of brain surgery to remove the tumor.

One type of brain tumor, called craniopharyngioma, is responsible for more than half of all cases of hypothalamic obesity. A craniopharyngioma is a rare and benign (noncancerous) type of brain tumor that develops near the pituitary gland, close to the hypothalamus. It’s usually diagnosed in children or older adults. About 60 percent of people with a craniopharyngioma eventually develop hypothalamic obesity.

Other types of brain tumors associated with hypothalamic obesity include:

• Gliomas — Malignant (cancerous) tumors caused by the abnormal growth of glial cells (cells that support brain tissue)
• Hamartomas — Benign tumors that develop on the hypothalamus
• Pituitary adenomas — Benign tumors that develop on the pituitary gland

Brain Injury

Weight gain is common in people who experience a traumatic brain injury. Trauma can cause bleeding, inflammation, and swelling in the brain that damages the hypothalamus. Common causes of traumatic brain injury include car accidents, falls, assaults, and sports injuries.

Genetic Conditions

Some people are born with a genetic condition that causes hypothalamic dysfunction. For example, Prader-Willi syndrome is a rare genetic condition that is present from birth but begins to affect children between the ages of 2 to 6. This condition can cause problems with metabolism and developmental delays.

What Are the Signs and Symptoms of Hypothalamic Obesity?

The symptoms of hypothalamic obesity can differ from person to person. Rapid weight gain is the most common symptom of hypothalamic obesity. Symptoms that can lead to weight gain include:

• Hyperphagia (excessive or uncontrollable appetite)
• Not feeling satisfied after meals
• Excess weight gain even with calorie restriction and exercise
• Exercise intolerance (limited ability to participate in physical activity)

Symptoms of Related Conditions

Some people may have additional symptoms related to a brain tumor or disruptions in hypothalamic regulation of other body functions, including:

• Trouble sleeping and daytime sleepiness
• Extreme tiredness
• Feeling too hot or too cold
• Difficulty regulating heart rate and blood pressure
• Early or delayed puberty in children
• Electrolyte imbalance (unbalanced mineral levels in your blood)
• Seizures
• Vision problems and blindness
• Headaches
• Confusion

Who Is at Risk for Hypothalamic Obesity?

The risk factors for developing hypothalamic obesity are related to the risk of developing a brain tumor, injury, or genetic condition. Children aged 5 to 14 years are the group most commonly diagnosed with hypothalamic obesity. The diagnosis is usually related to a brain tumor in this age group.

Craniopharyngioma, the most common condition associated with hypothalamic obesity, doesn’t have any known risk factors. Some older, traditional types of brain surgery to treat brain tumors may have a higher risk of causing hypothalamic obesity compared to newer techniques.

According to Mayo Clinic, the groups at the highest risk of traumatic brain injury include:

• Children younger than 4 years
• Young adults
• Older adults at risk of falling
• Males of any age

Additionally, you may be at risk of hypothalamic obesity if you have a family history of an associated genetic condition. Genetic testing may help you understand your risk.

How Is Hypothalamic Obesity Diagnosed?

Your healthcare provider may suspect hypothalamic obesity if weight management interventions haven’t helped you lose weight or if you have rapid weight gain associated with a brain injury or brain tumor. Blood tests and imaging tests can help your healthcare provider make a diagnosis.

Blood Tests

Blood tests for hypothalamic obesity will check for health conditions caused by hormone deficiencies, often related to hypothalamic dysfunction, such as:

• Diabetes insipidus — Low levels of the hormone vasopressin
• Adrenal insufficiency — Low levels of the hormone cortisol
• Hypothyroidism — Low levels of thyroid hormone
• Growth hormone deficiency — Low levels of growth hormone
• Hypogonadism — Low levels of sex hormones (estrogen and testosterone)

You may also need blood tests to check for complications of obesity, including:

• Type 2 diabetes
• Fatty liver disease
• High cholesterol

Imaging Tests

Imaging tests, such as a CT scan or an MRI, create an image of your brain. Your healthcare provider can use an imaging test to check for signs of a brain tumor or traumatic brain injury.

How Is Hypothalamic Obesity Treated?

There aren’t any treatments specifically approved for hypothalamic obesity. Treatment of hypothalamic obesity focuses on treating the underlying cause and finding the right weight loss strategy that works for you. However, you may have a difficult time losing weight with diet and exercise alone.

Managing Underlying Conditions

Appropriate management of underlying conditions related to hypothalamic obesity can help prevent further damage to the hypothalamus. Specific treatments depend on the underlying cause.

People with a brain tumor may need surgery to remove the tumor. After surgery, regular imaging tests are typically needed to check if the tumor has come back. Treatment after a brain injury may include medications, surgery, and rehabilitation programs. Hormone deficiencies related to a genetic condition or complications of brain tumors can be managed with hormone replacement therapies.

Appetite Suppressant Medications

There are no medications approved for the treatment of hypothalamic obesity.

Medications to suppress the appetite can help manage excessive hunger. Several glucagon-like peptide 1 receptor agonists, commonly known as GLP-1 drugs, have been approved to treat general obesity. These medications help suppress the appetite by slowing how fast food leaves the stomach and increasing the feeling of fullness.

Although these medications are often successful in people with general obesity, they may not be as effective in people with hypothalamic obesity. A clinical trial of GLP-1 drugs in children with hypothalamic obesity found no significant change in body mass index (BMI) after one year. While children taking GLP-1 drugs did have reduced food intake, their bodies used less energy. More research is needed to learn if newer GLP-1 drugs may be helpful.

Weight Loss Surgery

Gastric bypass surgery is considered the most effective treatment for hypothalamic obesity. This weight loss surgery involves surgery to reduce the size of your stomach. People with hypothalamic obesity may lose about 25 percent of their body weight after this treatment.

Talk With Others Who Understand

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