But there is also a downside we should not ignore.
This is one more step on the path we've been on that leads away from accepting responsibility. It's never anybody's fault for anything: I didn't get irresponsibly drunk; my genes made me do it. And, I don't have anger issues; I suffer from social anxiety disorder. And, I can't help smoking; I have an addictive personality. Now add I eat too much because my disease hasn't been treated to the list.
A small percentage of obesity is caused by genuine medical conditions. But the overwhelming majority of it comes from eating too much, making poor food choices and not exercising enough. The more we think of obesity as a disease, the less likely we are to acknowledge the simple need to make responsible use of our free will.
As we have come to understanding more about the human genome, there has been an unfortunate tendency to explain everything by heredity. How can we be held responsible for bad behavior when it is programmed into our very being?
That's not exactly the key to a healthy, civilized society. Yes, there is a genetic component to everything. But genetics only predispose; our biology does not predetermine. We all have tendencies, but we also have the obligation to accept the consequences of our decisions.