In the U.S., obesity has risen steadily over the past decades, from 30% of adults in 2000 to 42% of adults in 2018. Obesity in children has risen as well, from 14% in 2000 to 19% in 2019. People think about obesity mostly in the context of calories—if you eat more calories than you burn, you’ll gain weight. To deal with obesity, many clinicians will advise reducing the number of calories eaten and increasing exercise. Diet and exercise undoubtedly play a major role in obesity levels. However, the persistent rise in obesity in the U.S. indicates to Heindel that something besides diet and exercise is at play. But with the lack of available tests to determine whether a person might be suffering from obesogen exposure or not, scientists are still unsure of the role that obesogens play in proportion to other factors like diet and exercise. “There are so many multiple different factors going on, that we can't pinpoint which one is doing what,” said Heindel. Related: BPA—what you need to know Doctors and healthcare workers, he added, are “focused on the fact that obesity is due to over-eating. So if you are obese, you can take drugs, you can be on a diet, or you can have surgery. And that's supposed to take care of the obesity.” Bruce Blumberg, a professor of developmental biology at the University of California, Irvine and an author on the reviews, agrees. “That’s still the view of the medical community, that obesity really has everything to do with calories and activity and not much to do with anything else,” he told EHN. The Centers for Disease Control, for example, does not list obesogens as a driver of obesity; instead, it lists diet, activity, sleep, and genetics. Ryan Baldwin, a spokesperson for the American Chemistry Council, an organization representing more than 190 chemical companies, pushed back against the new reviews. “The prevailing view among the mainstream medical community is that obesity results from an imbalance between energy intake and expenditure caused by poor nutritional choices and insufficient exercise,” he wrote in a statement to EHN. “The evidence to support this view is much larger and of much higher quality compared to the evidence cited by Heindel [and co-authors] to support their obesogen hypothesis.”