If you could point me to the website where I can get my appointment for my 30 second diet that will massively reduce my risk of being hospitalised this winter I'd be grateful.Because why else are you worried about the unvaccinated?
If you're concerned that they will overwhelm hospitals then mandatory diets, mandatory exercise or other mandatory lifestyle changes would have a bigger impact on the NHS than mandatory vaccination, especially given the number of unvaccinated is quite small. Also bear in mind the number of hospitalisations has been dropping for some time and is not out of kilter with respiratory virus hospitalisations for this time of year.
Perhaps we should make life difficult for those who are overweight? Refuse to serve them any dish over a certain number of calories? Only allow them water in restaurants and no alcohol or fizzy drinks?
If you're concerned about getting it yourself then you're just as likely to get it from somebody who has been vaccinated as you are from somebody who hasn't. The vaccines protect you, but somebody who isn't vaccinated is no more dangerous to you than somebody who is.
And if you're worried on their behalf about them dying, well frankly that's their choice and their risk.