Most people know that obesity is linked to an increased risk of diabetes and heart disease. But did you know that there’s a link between asthma and obesity? According to both the Centers for Disease Control and Prevention and the American Academy of Pediatrics, asthma is far more common in obese adults and children than in non-obese adults and children. Approximately 7% of American adults with a body mass index (BMI) in the normal range (18.5-24.9) has asthma, compared to 11% of adults with a BMI of 30 or greater. Adult obesity causes approximately 250,000 new cases of asthma each year; among children, approximately 25% of all new asthma cases are directly attributable to asthma. Find out more about the asthma and obesity link, including what’s known about asthma and obesity in childhood. Obesity can cause asthma. Researchers have identified a few mechanisms that may explain the link between asthma and obesity: Fat produces inflammatory substances. Asthma is a disease that’s characterized by inflammation of the airways. Scientific studies have shown inflammatory substances produced by fat affect the airways and asthma symptoms. Genetics probably play a role. Research has shown that genes linked to chronic inflammation may be more active in people who also have obesity. Scientists also know that obese mothers are more likely to have children who have asthma. According to one study, maternal obesity and weight gain is associated with a 15 to 30% increased risk of asthma in her children. Other obesity-related medical conditions might contribute to the development of asthma. Obesity can cause—or worsen—GERD (gastroesophageal reflux disease) and sleep apnea. Both of these conditions increase the risk of developing asthma. Vitamin D deficiency is related to both obesity and asthma. Studies have found babies born to mothers who are vitamin D-deficient are more likely to be obese than infants born to mothers with normal vitamin D levels. Researchers have also learned that giving pregnant women vitamin D supplements slightly decreases the risk of their children developing asthma by age 3. Microbiome changes may facilitate obesity and asthma. The microbiome is the community of microorganisms that lives inside us and on our skin. Recent research has revealed all kinds of links between the microbiome and disease, and scientists suspect that changes in the microbiome may play a role in the development of both obesity and asthma. Asthma and obesity increase the risk of poor health. Nearly 60% of adults with severe asthma are also obese, and obese people with asthma are more likely to report poor asthma control. People with obesity and asthma are also more likely to be depressed, use more medication, and experience serious symptoms. Studies haven’t yet fully untangled the link between obesity, asthma, and poor health. Are people with severe asthma more likely to be obese because their breathing challenges limit their physical activity, or does obesity somehow worsen asthma symptoms? There is truth to both situations, but more research into asthma and obesity is necessary to know all the answers. Unfortunately, there also is a stigma towards obese people, and this includes the medical field. Studies have found many healthcare providers unconsciously treat obese patients differently than patients whose weight falls in the recommended range. It’s possible this unconscious bias extends to asthma diagnosis and treatment. Taken together, the underlying biology of asthma and obesity, as well as personal perception and perhaps bias may help explain why obese patients do not experience the same level of asthma control as thinner patients. Coordinated medical care helps manage asthma and obesity. According to the American Pediatric Association, there are few preventable asthma risk factors. However, in children at least, preventing the onset of obesity (or reversing obesity if it has already occurred) may prevent asthma. Your healthcare provider can help you determine a healthy weight for your child and discuss feeding and activity recommendations. Exercise itself may help obese adults and children with asthma. Regular physical activity over at least a 10- to 12-week period may decrease asthma symptoms at night. If you are not used to exercising, start slow and build upon your endurance and fitness level over time. Your doctor can provide more specific advice based on you or your child’s overall health. Losing weight may also improve asthma control. Patients who lose weight via diet and exercise typically experience improvement in asthma symptoms. So do obese patients who undergo bariatric surgery. One study of just over 2,000 patients found that bariatric surgery led to a 60% reduction in risk of an asthma attack. People who have asthma and obesity will benefit from coordinated medical care. An experienced healthcare provider can help you lose weight and get your asthma under control.