It is a curious legal position. Were he adjudged sane, we'd have to let him starve himself to death, because forcibly feeding him is assault . And for those who think that's because it would be interfering with his "human rights", and it's those damn foreigners interfering, with that Human Rights Act we signed up to, you are wrong yet again and for the umpteenth time ! It was established as law in the time of the suffragettes.And it's why we didn't force-feed IRA hunger strikers, though it would provide a martyr to the cause.
As it is, he isn't and we can and must. It's a fair bet that if we left him to die, he wouldn't, because there is evidence that he's getting soup and toast, which he makes for himself, now. He is an attention seeking narcissist, which is part of his illness. I'd be inclined not to feed him and thus to deny him the attention he craves.