And there was also nothing stopping him buying his own bread etc either, I feel bad for her as she clearly needs help but I don’t have sympathy with him
That's completely your prerogative to not have sympathy for him.
Having lived with someone who was a little (or even worse) like Niomi, I can tell you it's a shit situation to find yourself in though. I lived with a roommate who constantly commented on food choices, tutted when I reached for a certain food, explained all the ways in which things might be good or bad for me etc. They would tell me how my choices made them feel horrible and it was "only to help me". So naturally you try to see their point and make them feel more at ease with your own behaviour. Especially when they seem to have issues around food. That is for sure not the right thing to do at all, suggesting they get help would be far more benefical. Slowly but surely it does wear you down and you don't even realise how much you do change in terms of your food habits. Which, in my case at least, made it so much worse for everyone involved. I should have just insisted they get help and kept doing what I was doing. I realise that now, but it was difficult to step out and see the bigger picture stuff.
And that person was only a roommate to me. A partner who lived with me would have been a lot more intrusive, I guess.
Everyone is responsible for their own choices, for sure. But it's sometimes not that easy, because you don't even realise how much control that person exerts over you, especially when it's always done under the guise of only wanting the best for you and it's all because "you're going to be so much healthier, why would you not want that?" And I have no doubt that Niomi is convinced that she was doing the best for him with that behaviour. You are completely right, in my opinion, in saying that she does need help because ultimately he can, and did, step away from the control and she is still stuck in that place, from what it seems. I guess I am trying to say that sometimes, especially if you love that person, it's not as easy as just going to buy that bread or just not caring. My roommate had breakdowns every time I baked cake or cookies etc and I slowly stopped doing it, because I felt so bad that it made them suffer
Like so many pointed out on this thread before, that might be one of the reasons why lockdown took such a toll on them as a couple. They were together constantly and there was no let up of the control and they don't seem to have had very good communication between the two of them. Who knows what happened behind closed doors, but it just seems that lockdown brought out all the cracks in their union.