Did anyone ever tell you that you have a “lifestyle disease” because you have type 2 diabetes? Even if no one ever said that to your face, you can be sure that some people have thought that and even said so behind your back.

Lots of people see type 2 diabetes as preventable if only we would eat less. They think that diabetes results from a choice, just as other lifestyle choices like cigarette smoking and heavy alcohol consumption lead to other diseases. It’s blame-the-victim time.

Even the...