Obesity can increase the risk of severe COVID-19. It may also increase a person’s risk of developing the virus due to a weakened immune system.

About 41.9% of the adult U.S. population had obesity between 2017 and 2020, according to the Centers for Disease Control and Prevention (CDC). Evidence suggests that obesity can increase the risk of developing a serious infection from COVID-19.

This article reviews what a person needs to know about the effects that obesity has on COVID-19.

Coronavirus data

All data and statistics are based on publicly available data at the time of publication. Some information may be out of date. Visit our coronavirus hub for the most recent information on COVID-19.

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According to the CDC, obesity can weaken the immune system. This can place a person at greater risk of contracting the coronavirus that causes COVID-19.

This means people with obesity may need to protect themselves more from exposure to the virus by wearing a mask and washing their hands.

Obesity is a known risk factor for severe COVID-19. According to the CDC, obesity may:

  • triple the risk of hospitalization
  • make breathing and ventilation more difficult
  • increase the risk of death and need for stays in the intensive care unit (ICU)

In addition, the CDC notes that people with obesity accounted for about 30% of all hospitalizations for COVID-19 between the beginning of the pandemic and November 2020.

Children with obesity may also have a higher risk of severe COVID-19.

According to a 2021 study, children with obesity had a 3.1 times higher risk of hospitalization and a 1.4 times higher risk of severe illness when hospitalized. This means they either required invasive ventilation, ICU care, or died in the hospital.

Learn more about COVID-19.

Evidence suggests that obesity can impair the immune system.

In a 2018 study, researchers looked at how systemic inadequate (malnourished) and overabundant (obesity) nutrients affect T cells and other aspects of the immune system. Researchers noted that obesity is associated with:

  • increased inflammation
  • increased risk factors for cardiovascular disease
  • decreased protective immunity

In other words, a person with obesity may have a more difficult time fighting off an infection, such as COVID-19.

Read more about obesity.

According to the CDC, obesity rates have remained high and increased over the past several years, including during the COVID-19 pandemic. In some cases, obesity rates more than doubled from 2018 to 2021.

Obesity and overweight rates have also risen in children. According to a large 2021 study, the rate of body mass index (BMI) nearly doubled during the COVID-19 pandemic compared with a pre-pandemic period in children between the ages of 2 and 19 years.

Children with obesity or overweight had the most pronounced increase in BMI during this time.

Preventing COVID-19 can be an important first step for people with obesity or overweight.

A person with overweight or obesity can decrease their risk of COVID-19 by taking the following steps:

  • staying home when unwell
  • staying up to date on immunizations for infants, children, and adults, including COVID-19 vaccines
  • washing hands regularly
  • wearing a face mask when physical distancing is not possible
  • keeping a distance of 6 feet (1.8 meters) between people and avoiding crowds, when possible
  • sanitizing, cleaning, and disinfecting surfaces
  • covering the mouth when coughing

A person may also consider taking steps to lose weight, which can help improve overall health and help prevent severe infections from occurring.

Some steps that may help with weight loss include:

  • talking with a doctor or nutritionist to create an eating plan
  • increasing physical activity throughout the day or week
  • discussing weight loss medication with a doctor
  • setting goals and reasonable expectations
  • joining weight loss programs or organizations
  • discussing possible intervention devices with a doctor, such as a gastric balloon system, or bariatric surgery

Learn more about weight loss.

A person may want to order at-home COVID-19 tests. When symptoms are not severe, it may help a person avoid a doctor’s visit and help prevent transmitting germs to others by staying home from school or work.

A person with COVID-19 symptoms may want to consider contacting a doctor for treatment. A doctor can diagnose and recommend treatments. They can also confirm an at-home test diagnosis.

A person should seek immediate emergency care if they experience trouble breathing. This could be a sign of severe infection.

A person with obesity or overweight may have a higher chance of severe COVID-19. They may also have a higher chance of developing an infection when exposed to the coronavirus.

A person can help reduce their risk by avoiding crowded public spaces, getting vaccinated, and avoiding people with known exposure to COVID-19 or other illnesses. Washing their hands regularly and wearing a mask can also help people prevent COVID-19.

If a person develops COVID-19, they should stay home from work or school, if possible. They may want to talk with a doctor for diagnosis and treatment options. A person with severe symptoms that cause breathing issues should seek emergency medical attention.