What about people that are severely underweight through no fault of their own?  I'm fed by a tube into my small intestine to bypass my paralysed stomach but as my intestines are almost as fucked as my stomach, I still can't physically absorb enough calories. I barely manage to maintain a BMI of 15 to 16 and cannot get above that no matter what I do.  Should I be punished and charged extra for something that is completely out of my control; treated the same way as the obnoxiously fat fucks that are eating themselves into ill-health? Just because landwhales and I both have one foot in the grave due to weight doesn't mean that we're equally at fault for our problems. I like the idea but the reasons behind the issue for those that are underweight as opposed to overweight are much more complicated and variable than simply "doesn't eat enough" vs "eat too fucking much". I think it would need to be judged case by case as I'd definitely die long before I ever managed to pay for the expenses involved in keeping me going, especially with a "surcharge".  Unless we're just going to say "fuck it" and go the eugenics route of "you deserve to die because you're fucked up".