Endometriosis causes tissue similar to the uterine lining to grow elsewhere in the body. It can cause chronic pain, heavy, irregular periods, and infertility. Some people also report weight gain and bloating.

Little research has explored why endometriosis might cause weight gain. Anyone with endometriosis who suspects that it is causing weight gain or making weight loss difficult should speak with a doctor.

It may be worth noting that other conditions, such as polycystic ovary syndrome (PCOS), can mimic the symptoms of endometriosis and lead to unexplained weight gain.

This article explores how endometriosis might cause weight gain and how to reach and maintain a healthy weight while living with the condition.

Plenty of anecdotal evidence has linked endometriosis to weight gain. Scientific research has yet to explain this link.

By contrast, some studies show that discomfort from endometriosis can lead to weight loss in people with pain and nausea that limits how much they eat.

Meanwhile, a study from 2014 confirms that endometriosis contributes to weight gain and poor body image, as reported by people with the condition.

Mainly anecdotal evidence suggests that endometriosis can cause weight gain in at least five ways. They are:

Bloating

Bloating and fluid retention are common endometriosis symptoms.

Bloating can make a person’s weight fluctuate and make them look and feel heavier. Bloating may also change how clothes fit. Many people notice that it is worse immediately before or during their period.

Some people with frequent bloating may gain as much as 10 pounds in a year, though there is overall little research on the subject.

Endometriotic growths on the bowel or other abdominal organs can cause inflammation that leads to bloating, constipation, and other gastrointestinal symptoms that may contribute to weight gain.

Estrogen

There is conflicting scientific evidence about estrogen and weight gain.

Endometriosis is an estrogen-dependent disease, which means that its symptoms may worsen when estrogen levels are higher. However, there is no evidence that this can cause weight gain.

There is some evidence that when estrogen levels plummet, during menopause, for example, people often develop more fat in the abdomen.

At the same time, other research indicates that taking estrogen supplements as part of hormone replacement therapy after menopause may help reduce abdominal fat. It is unclear whether any of this contributes to overall weight gain or loss.

Medication for endometriosis

Over the years, several studies have demonstrated that some endometriosis treatments may cause weight gain.

The most common treatment for endometriosis is hormonal birth control. Some forms may cause weight gain, depending on the type and how the body reacts to the hormones.

For example, treatment with a combined pill, which contains synthetic estrogen and progestin, and treatment with progestin alone may cause weight gain. In other cases, these pills may cause bloating, which can feel like weight gain.

Most recently, researchers found that dienogest (Visanne), a type of oral progestin, can lead to weight gain and vaginal bleeding. And the injectable form of progestin-only birth control, Depo-Provera, can cause weight gain, as well.

Endometriosis and PCOS

PCOS causes some similar symptoms to endometriosis. It stems from a hormone imbalance and, like endometriosis, can cause painful periods.

Other symptoms of PCOS include:

PCOS may cause weight gain due to insulin resistance and metabolic abnormalities.

It is also possible for people with endometriosis to have PCOS, as well. Anyone with irregular periods, painful periods, or difficulty conceiving should seek testing for both conditions.

A low glycemic index diet may help with PCOS-related weight gain. And some people find that hormonal birth control pills help with the symptoms. However, these can also cause weight gain.

Pain

Pain is the most common symptom of endometriosis. For some people, the pain is so severe that daily activities are very difficult.

Pain can lead to weight gain in a number of ways. For example, it can make it hard to exercise and stay active.

And people with lasting or frequent pain have a higher risk of mental health conditions, such as depression. One depression symptom can be overeating or eating unhealthy food. Weight gain is also a side effect of several anti-depressants, and some pain medications.

In addition, people with chronic pain may struggle to sleep. Researchers have linked a lack of sleep over time with a higher body mass index.

Many natural and alternative health websites promise to help people with endometriosis lose weight through special diets.

While there is some evidence that having a healthy diet can reduce some symptoms of endometriosis, such as pain and fatigue, there is no clinical evidence that any diet can help a person with endometriosis lose weight.

To lose weight, a person needs to burn more calories than they consume. Some strategies include:

  • Increasing physical activity: Walk as often as possible and break up long periods of sitting. The Physical Activity Guidelines for Americans recommend doing 150–300 minutes of moderate-intensity cardio exercise or 75–150 minutes of high-intensity cardio exercise each week. They also recommend doing strength training on at least 2 days a week.
  • Having a healthy diet: Eating a variety of filling, lower-calorie foods, including lean proteins, vegetables, fruits, and whole grains, can help with weight management. Also, opting for high fiber and high protein foods may lead to fewer food cravings.

A person with endometriosis and questions about weight loss should speak with a doctor, especially if they have other health conditions, such as PCOS.

The following answers provide some insight into endometriosis and weight gain.

Does endometriosis affect appetite?

Endometriosis may affect a person’s appetite. The condition can cause digestive issues, such as nausea and constipation, which may affect hunger.

Does endometriosis cause a belly pooch?

There has been very little scientific research into endometriosis’ effects on weight gain. However, a person may gain some fat around their midsection or lower.

How does endometriosis surgery affect weight?

Indirectly, having surgery to remove the characteristic growths may help with pain and reduce bloating. This, in turn, may help a person lose weight. However, no clinical evidence confirms this.

What other symptoms does endometriosis cause?

In addition to pelvic pain and bloating, endometriosis can cause constipation, pain during bowel movements or urination, and infertility. Learn more about endometriosis symptoms here.

Endometriosis is a chronic condition, but a number of treatments, including hormone-based medications and surgery, can help ease the symptoms.

Many people with endometriosis feel frustrated by the lack of research about endometriosis-related weight gain. A doctor who listens and takes symptoms seriously might be able to suggest an effective weight management strategy.