One of adopted daughters has cerebral palsy and has significant paralysis on her right hand side. She has virtually no use of her right arm and little use of her right leg. Yet, despite this, she is an avid runner. She has consistently ran 12 to 20 miles per week since she was 10. She is 15 now, and here in a few minutes I will be going to one of her track meets. She also eats a very good diet, strength trains, even goes on wilderness backpacking trips with me.
It would be flat out immoral to charge someone like her more for health insurance simply because she has CP. However, let's look at the other side of this. Every year, type 2 diabetes, an entirely preventable disease, costs us hundreds of billions of dollars. So why the hell should someone takes poor care of themselves, doesn't exercise, eats terribly, and is obese and headed for type 2 diabetes as a result, pay the same rate as my daughter? If your poor health choices cost you nothing, you have little incentive to ever make better ones. However, if your told you are clinically obese, with high blood pressure and borderline diabetes, if you attain a 10% reduction in weight, you can get the preferred rate. Or, if you are a smoker, and you are told that if you do smoking cessation, you can get the preferred rate, otherwise you are going to have to pay the rate that actuaries determine the risk your choices justify.
This isn't micromanagement of people's lives. No one is saying are you wearing the right kind of running shoes, or are you stretching properly, what kind of neighborhood did you go on a walk through and so on. It is simply looking at the biggest causes of preventable disease, and saying just like any other form of insurance, your rate reflects your poor lifestyle choices.
If you get a dui you pay a higher auto insurance rate. We don't charge a contentious driver the same rate as someone that has racked up 10 speeding tickets.