Society teaches us from an early age that being overweight is bad for your health. But for a little over a decade, doctors have been reporting evidence of the “obesity paradox”: cases of overweight or mildly obese patients faring better with several health conditions than their thinner counterparts.

Quartz recently published a feature story exploring the phenomenon that includes insights from several physicians. Carl Lavie, a cardiologist in Jefferson, Louisiana, was one of the first clinicians to get a paper published describing the paradox. Since then, dozens of studies have been released supporting its existence. It’s now a commonly held belief in the medical community that being overweight can protect patients against issues like burns, stroke, hypertension, pneumonia, and heart disease.

As you may have guessed, these findings have stirred up their fair share of controversy. Many scientists have taken a strong stance against any evidence supporting the paradox, saying it can be explained away by other factors. One popular theory is that overweight people are receiving better treatment than thinner people, but when you look at actual studies on the care received they tend to show the opposite

Even if heavier people are more likely to survive life-threatening conditions like heart disease, they’re also more likely to be diagnosed with them in the first place. But weight isn’t the only factor that influences a person's chances of having these issues. Add that to the fact that a strong correlation between weight and disease only appears in the morbidly obese and the health benefits of being overweight start to look more convincing. 

There are others who say that smokers and sick people, who tend to be thinner but also less healthy, skew the data. While this could be possible, the studies on the issue aren’t concrete enough to say for sure. The data that’s been collected on the obesity paradox, however, is hard to contest. 

Katherine Flegal, an epidemiologist at the U.S. Centers for Disease Control and Prevention, has examined hundreds of mortality studies including information on body mass index (BMI). What she found is that patients in the overweight and mildly obese classifications suffered the lowest mortality rates. Her study, published in the Journal of the American Medical Associationanalyzed data from nearly 100 studies looking at close to 3 million participants. 

But just because researchers buy into the phenomenon’s validity doesn’t mean they’re any less perplexed by it. The medical field has used weight as a marker for health for a long time, but the obesity paradox suggests that the two may not be as intimately linked as we previously believed. In response to the findings, many doctors are now taking the “Health at Every Size” approach to healthcare. This initiative is built around placing a greater emphasis on healthy behaviors like nutrition and exercise. So don’t use this news as an excuse to switch to an all-ice cream diet.

[h/t: Quartz]