The thing with Japanese culture (China's too) is that just about everyone will go along with it if it's for the greater good of the people. This is how they are able to pass stringent measures such as this without any outcries of injustice.
As for the right to be fat, sure why not, but don't expect everyone and everything to be the same for your fatass, like airplane tickets - I honestly hope they do add in that extra fee for overweight passengers on flights. I have the right to be an asshole on these boards in a lot of ways, and I indulge in it, but I'm not naive about it and think that everyone is going to treat me the same way as a nice guy like Jeffster. (of course medical conditions are an exception to this, like gladular disorders and diabetes)
As for the efficacy of health care costs, I think that's a moot point for reasons mentioned and probably just politic rhetoric to get it passed. The REAL issue here about overweight people is how energy inefficient they are (in food costs, not just fuel) and how we cater to the sins of sloth in this country. I'm so tired of seeing fat people, as well as perfectly fit ones, ride the elevator up two stories when it would be better for them, as well as others, to just suck it up and take the stairs and get that extra bit of excercise. Walk instead of driving a half mile to the corner station or liquor store. It's not that hard, but people feel so entitled to do the bare minimum because they have a "right to be fat". Fine, be overweight, but don't be pissed when the whole that carries thier own weight and costs better than you do want to tax you for your extra burden. I hope Japan gets it passed.