Childhood obesity has been a well-known factor for an increased risk of asthma, but researchers have wondered what came first, the excess weight or the asthma? The proverbial chicken and egg debate led scientists at the American College of Allergy, Asthma, and Immunology (ACAAI) to publish their findings in the College’s scientific publication.

"The relationship between obesity and asthma in adults, which shows that being overweight and obese can precede the onset of asthma, is supported by a number of studies," the study’s lead author Perdita Permaul, and allergist at the American College of Allergy, Asthma, and Immunology said in a press release. "There isn't as much evidence for children, but the progression from obesity to asthma, rather than the other way around, seems probable."

Previously, doctors didn’t know if the constricting airways that asthma causes was the reason children were discouraged to exercise and then gained unhealthy amounts of weight, or if it was the other way around. Researchers have concluded that it’s more probably because children are overweight their airways are narrower and then develop asthma. Children who have asthma and other allergic diseases should not avoid exercise or sports participation just because of their condition, according to the ACAAI.

"Most kids who suffer from asthma also have allergies," Michael Foggs, the president at ACAAI, said in a press release. "These allergic responses in the lung can lead to symptoms of allergy. Coughing, wheezing, and shortness of breath are all symptoms that make exercise harder. We work with our asthma patients to make sure they are breathing well enough to exercise and play."

Childhood obesity rates are daunting and the high rates predict an ominous future for the rest of the country that currently has more than one-third obese adults. Obesity significantly increases the risk of heart disease, stroke, type 2 diabetes, and certain types of cancers, making it one of the leading causes of preventable deaths. Currently, there are 12.7 million children and adolescents between the ages of 2 and 19 that are obese, according to the Centers for Disease Control and Prevention.

"Higher BMI in mid-childhood could help explain some of the increase in asthma risk toward the end of the 20th century,” Raquel Granell, a research statistician at the University of Bristol, who recently published a study on the link between 5,000 children and asthma, told The Guardian. “Although the continued rise in obesity but with a slowing in the rise in asthma prevalence in some countries implies that other non-BMI-related factors are also likely to be important."

Granell and her team found for every extra unit on the body mass index (BMI) scale, the risk of developing asthma increases by 55 percent. Until this study, which was published in the journal PLOS Medicine in June, researchers weren’t sure if it obesity caused asthma or if it was just a coincidence that obese children also had asthma. Now that a causal link has been confirmed, researchers can move forward and treat the complex relationship and move forward to developing preventive measures.