Having an eating disorder such as anorexia nervosa can increase your risk of developing osteoporosis, but there are things you can do to help improve your bone health.

People who have anorexia typically don’t get the amount of nutrients necessary for their bodies to function, which can increase the risk of other health conditions, including osteoporosis.

Osteoporosis occurs when your bones lose strength and density and may result in fractures.

According to one 2019 study, 20% to 30% of people living with anorexia develop osteoporosis, while 50% to 90% develop osteopenia.

Osteopenia occurs when your bone density is lower than expected. If left untreated, osteopenia can lead to the development of osteoporosis.

Osteoporosis is a condition that causes the bones to become weaker and less dense. In the United States, more than 53 million people either have osteoporosis or are at high risk of developing the condition.

Throughout your life, your body breaks down bone cells and replaces them with new cells.

Sometimes your body may break down bone cells too quickly or replace them too slowly, which can lead to the development of weaker, less dense bones — that is, osteoporosis.

There are a number of ways that anorexia may increase your risk of osteoporosis:

  • Lack of nutrition: People with anorexia typically have insufficient nutritional intake, which means their bones might not get the nutrients they need.
  • Low estrogen levels: Estrogen is a hormone that plays a role in the development of healthy bones. People with anorexia tend to have lower estrogen levels.
  • Low muscle density: When you don’t get enough nutrients, your muscles may decrease in size and strength. Low muscle density is linked to osteoporosis because muscle force stimulates bones, which keeps them strong.
  • High cortisol levels: People with anorexia generally have higher levels of cortisol. High cortisol levels are related to osteoporosis, as it may increase your body’s reabsorption of bone cells.
  • Low levels of insulin-like growth factor 1 (IGF-1): IGF-1 plays an important role in bone growth during puberty and continues to support bone health throughout your life.

As the Royal Osteoporosis Society notes, anorexia often develops during adolescence or early adulthood, which is an essential time for bone development.

Your bones typically reach their peak strength near the end of your 20s, after which their density declines.

If your bones don’t develop properly when you’re young, their peak strength won’t be high, and you may develop osteoporosis later.

The most significant risk factor for osteoporosis is age. As you age, your body starts breaking down bone cells faster than it can replace them. This process leads to your body forming weaker, less dense bones.

Menopause is another risk factor for osteoporosis because, during menopause, your body produces less estrogen. The underproduction of estrogen can cause your body to break down bones faster than it produces them.

Other risk factors for osteoporosis include:

Although you can’t control all risk factors for osteoporosis, such as your age or sex assigned at birth, you may be able to reduce your risk by making certain changes, such as starting a smoking cessation program.

Whether you have an active eating disorder or are in recovery, you can take a harm-reduction approach to your eating disorder.

Harm reduction is about taking steps to protect your mental and physical health even if you’re not able to abstain from all anorexia-related behaviors.

You can:

  • Take calcium and vitamin D supplements: Although it’s best to get nutrients from food sources wherever possible, supplements may help make up for the nutrients your diet lacks. It’s best to use supplements only as guided by a healthcare professional.
  • Try meal replacement shakes: If you have difficulty eating solid foods, nutrient-rich shakes may be a useful alternative. Protein-rich shakes are a good idea, as protein is important for muscle and bone strength.
  • Exercise in moderation: Too much exercise can be just as bad for your bones as too little exercise. It’s best to consult with a healthcare professional before starting an exercise program, but most people will want to aim for moderate-effort exercise a few times a week.
  • Exercise responsibly: Be sure to warm up and stretch before exercising. If possible, avoid contact sports and exercises in which there’s a high risk of falling. Do small bits of weight bearing exercises as much as your joints will allow it, but don’t push yourself.
  • Avoid smoking and drinking alcohol to excess: Cigarettes and excessive alcohol can increase your risk of developing osteoporosis and other health conditions.

If you’re comfortable disclosing your eating disorder to a clinician, it may be a good idea to do so. They may have more personalized ideas on how to keep your bones strong and reduce your risk of osteoporosis.

If you think you have an eating disorder or disordered eating, it’s a good idea to reach out to a healthcare professional.

You could try speaking with a doctor or making an appointment with a therapist that has experience in treating eating disorders.

You don’t have to fit the diagnostic criteria in order to get help. Wanting help is reason enough to seek it.

There are a few indications that suggest you may need to ask a doctor to screen for osteoporosis. They may suggest a bone density test to determine whether you have the condition.

These warning signs and symptoms are:

  • Amenorrhea (a lack of menstrual periods) and anovulation (a lack of ovulation): If you menstruate, amenorrhea and anovulation can be an indication that your estrogen levels are low. Because estrogen is directly linked to bone health, these indications can mean you’re at risk of developing osteoporosis.
  • Symptoms of low testosterone: If you were assigned male at birth, low testosterone can affect your bone density. Keep an eye out for symptoms of low testosterone, such as fatigue, low libido, and hot flashes.
  • Weak and brittle nails or receding gums: Affected nails or gums may be an early symptom of osteoporosis, though it may be caused by something else.

You may also want to be on the lookout for later symptoms and signs of osteoporosis, such as:

  • Back or neck pain: Osteoporosis may cause compression fractures in the spine, which can cause pain in your back or neck.
  • Fractures: Fractures, or broken bones, that happen easily are a tell-tale sign of osteoporosis. You may easily fracture your bones from falling, exercising, or engaging in minor everyday movements.
  • Loss of height: Compression fractures of the back may shorten the spine, which can cause you to look shorter than you previously were.
  • Poor or stooped posture: Compression in the spine may cause your upper back to curve (kyphosis), resulting in pain in the back and neck. A compressed spine can also place extra pressure on your lungs and airway, making it harder to breathe.

How many people living with or in recovery from anorexia develop osteoporosis?

Research suggests that 20% to 30% of people who have anorexia develop osteoporosis. Furthermore, 50% to 90% of people living with anorexia develop osteopenia, which is low bone density.

How long does it take for anorexia-related osteoporosis to develop?

Because your bone density depends on your age, lifestyle, and other factors, the length of time it takes for anorexia-related osteoporosis to develop varies from person to person.

One study notes that bone density loss can begin in as little as 6 months after the onset of anorexia nervosa.

Is anorexia-related osteoporosis reversible?

Osteoporosis isn’t considered reversible or curable, but there’s a case study of a person with anorexia-related osteoporosis whose symptoms were reversed through prescription medication, supplementation, and lifestyle changes.

If you have anorexia-related osteoporosis, entering recovery may prevent further damage to your bones, particularly if you begin meeting your nutritional needs.

Lifestyle changes such as a nutrient-rich diet and appropriate exercise can help prevent your bones from weakening further. With that said, research suggests it’s possible to continue losing bone mass even after regaining weight.

Anorexia can increase your risk of developing osteoporosis, a condition in which your bones become weak and fragile. If you live with anorexia, you may experience a lack of nutrition, hormonal changes, and low muscle density. These factors can cause osteoporosis.

Entering eating disorder recovery and meeting your nutritional needs can help lower your risk of osteoporosis. Certain lifestyle changes, such as taking the correct supplements and avoiding cigarettes, can help prevent osteoporosis.

If you’d like to take the first step in recovery from anorexia, you can contact a therapist specializing in treating eating disorders. Alternatively, you can contact the National Eating Disorders Association helpline.

Sian Ferguson is a freelance health and cannabis writer based in Cape Town, South Africa. She’s passionate about empowering readers to take care of their mental and physical health through science-based, empathetically delivered information.