All this cooking "healthy food" discourse is reminding me of the WW2 reports that evacuated children refused to eat food that wasn't tinned, or fish & chips. There was so much snobbery and disdain for urban working class mothers, and their "inability" to cook for their families.
But even government reports at the time made clear that a) a lot of this was simply middle-class elitism, and a refusal to accept that evacuated children might want comforting food (John Welshman said these claims were "amplified out of all proportion by parochial snobbery")...
...and b) these urban working class mothers were living in one or two rooms with their children, working long hours, with no fridge and no oven -- perhaps only a sink and a hot plate. Of course they relied on tins. They themselves survived on sugary tea, and sliced bread & marg.
The Our Towns report - a copy of which sits in my office, a v. interesting piece of social policy research conducted by a committee of middle class women in 1943 - is critical of the "slum diet": white bread, tea, sugar, sausages, jam, & margarine. But it's cheap & filling food.
Not only is it cheap and filling, but, it can be cooked on a hot plate, bought when needed and stored in one cupboard. Rationing definitely improved working class people's diets but what really helped long-term was housing reform, cheap white goods, supermarkets and the NHS.
TL;DR: you can't talk about food without talking about access to time and resources as well as raw ingredients, you can't talk about food without talking about class.
(On the refusal to accept that evacuees might want comfort -- there are also loads of middle-class complaints that evacuated children are wetting the bed & how this shows they are developmentally stunted. The fact that they might have been frightened never seems to have come up.)
(These are children who have been taken away from their parents -- who they are told are staying in a place of mortal danger, or being sent off to fight -- and sent to quite literally random families in random places, for an unknown period of time. *Of course* they wet the bed.)