Ok, I see your point. But how far will you take the it? Should they pay for your seat-belts in your car? We know that accidents get worse if you're not strapped in.
We also know that pet-owners have a longer statistical life-expectancy and remains more healthy in old age. Should the insurance be required to pay for my dog?
Slippery slope arguments are weak unless you can show a direct link to causation.
Your examples are outlandish and irrelevant. Irrelevant to your point, even. If the point you're making is that you shouldn't have to pay for other people's choices, it's already been demonstrated that that is how insurance works, so get over it.
This tangential point you're making is grasping at straws - the legislation isn't asking insurance companies to pay for things that reduce the risk to their customers - and thus, themselves. That's something that's in THEIR interest, but it's not what's being proposed.
Some insurance companies already do things to promote healthier living in its members, for example, by offering subsidised gym memberships, discounts on driving lessons (in some cases, free lessons), etc, etc. Doing so is actually in the interests of those companies, because healthier people result in less insurance claims, safer drivers result in fewer accidents (and again, fewer claims).