Health is not a virtue. It’s a privilege (and one the disabled don’t have). Fuck that. You don’t have to be healthy. You don’t owe it to anyone. Why do we so often value “taking care of yourself” over qualities like patience, honesty and kindness? Self-care is great, but it’s not a measure of your worth. Working out and eating “right” do NOT make you a better person. And what you or I do with our bodies is nobody’s business, anyway.
I think that what's being said here touches on some interesting points, but I still think it misses the mark to a degree. First, you're right--it's no one's business what you do with your body. But I don't actually think as a society we value "taking care of yourself." When people say "taking care of yourself," what they're really saying is "Please change yourself so that I am less uncomfortable with how you are." Those two are not synonymous. I'd argue that as a society we do not encourage people to take care of themselves enough.
Taking care of yourself, or self-care, does not necessarily mean dieting or exercising to lose weight or to get healthier or to change your different body (whether differently abled or fat or too skinny or whatever). Self-care might mean reminding yourself that these messages that society sends you are absolute B.S. Self-care might mean relaxing or taking a bath (not for hygienic reasons, but because it feels good). Self-care means valuing yourself in spite of the fact that society says you aren't worthy. If you don't perform self-care, you will (and I say this from my own personal reflections) experience burn-out and depression. Some people can and do experience ill-health because they do not take care of themselves. I have been there. Self-care has and will help me in the future.
If you don't take care of yourself, how can you have patience and kindness for very long? That's just what I don't get. It's a lesson that I continue to learn more and more every day, and it's not something that is not exclusive only to people with body privilege or monetary privilege or any other kind of privilege (except, perhaps, mental health privilege). Be kind to yourself first in the way you know how, in a way that is comfortable for you, in a way that is right for you and your health as is.
Oh, and just one thing to add... Being disabled? It doesn't mean someone is unhealthy. It's an easy assumption to make, but its just that: an assumption.