If you only focus on diet and exercise you’re missing a huge influence—chemicals in our environment that promote weight gain.

When you think about the causes of overweight and obesity, conditions that now affect the majority of Americans, two factors likely come to mind immediately: dreadful dietary habits and lack of exercise. This is what I call the “orthodox wisdom” that we hear all the time.

But what if I said you are wrong? Well, at least not 100 percent right. You’re missing a huge influence that has been driving the obesity epidemic for the last half century, and it has nothing to do with a penchant for sitting on the couch eating potato chips and watching television. It has to do with obesogens—chemicals in our environment that promote weight gain.

No one wants to be fat, but most of us are, despite working hard to eliminate unwanted pounds. Something is wrong with this narrative.