Very good post, AnnePerkins.
I haven't seen the programme, but one thing that occurs to me is that there is still a general assumption when healthier/cheaper food is being discussed that the wife/mother will do the cooking. I can imagine that in some families where she already has to take on a disproportionate amount of housework and childcare despite also working full-time, cooking is one thing that a woman might be unwilling to take on. Or, to put it better, one area where a quick alternative exists so she takes advantage of it.
The more I see and hear about these kinds of programmes the more I realise it is about a lot more than just food, or just cost.
Once upon a time lots of people had a canteen at work. They could eat a full (subsidised) meal at lunchtime and have a light dinner at home, so they probably didn't cook any more than people do now, but were still healthier.
I reckon most of us really did eat a lot less meat, years ago, but probably better meat. My grandmother grew up very poor and had a lot of saturated fat (bread and dripping, butter etc) and very little meat. However what they did have was stuff like wild rabbit and organic meat (because no one could afford the kind of antibiotics etc they give to animals now).
When I go to my father's country now, a lot of people still eat like that: things are flavoured using bones and animal fat but the amount of actual meat in the dish is very little. There are more vegetable and carbs, out of pure necessity. Also, people there eat far less sugar, and hardly any sugary drinks. I lose between half and one stone there every time I go.
Here, it can be a battle sometimes to find anything to eat that isn't high fat and high sugar. The UK is seriously confectionary mad, it is everywhere, and so is the advertising. I remember one awful motorway journey when we were badly delayed and I rushed into a service station to try and find a snack for the children, thinking that milk, apples or crackers would be easy to find. There was nothing in the whole place except crisps, burgers or sweets. No milk, no fruit, no nuts, not even plain cake or a scone. That's an extreme case, but it tells you quite a lot about what the average Briton must be in the habit of buying.