How will they implement new cost for obese people?

I was just reading an article about insurances raising the cost for smokers, obese people and people with high blood pressure.
Now heres what I am wondering. Most people carry a little extra weight by a certain age and may be consider obese even if they are healthy. My son for example is solid rock muscle but on a scale he is overweight for his height.
He is extremely healthy and works out. (In his case its not a problem because he is in the military.) But for the average person who has to pay for his insurance and who may seem overweight but really isn’t, what are they to do.
Also not ever person with high blood pressure eats poorly or has it because they are purposely unhealthy. I’ve known thin people with high blood pressure and it just runs in their family.
My point, is this just a scam for raising rates? Will asthmatics be penalized, or people who have a family history of some inherited disease?
I read an article that said that rates will raise up to 2 thousand extra per year for these individuals.
Well going back to the original question. Which was how will they implement this. Not every doctor does an accurate obesity test. Many just look at your weight and your height and that is it. I’ve known skinny people who are unhealthy and overweight who are very healthy. So will it simply come down to what a scale says?