We are on the breadline, I have a maximum of £50 for food for a family of 6 (7 during uni holidays) and none of my children are small, 2 are adult males, another 2 are teens and the youngest is 10. I have ME so have poor health, can't shop around or anything like that; don't have a car; live several miles and several pounds in bus fares from the nearest supermarket, even if I was fit enough to go there; only have an extremely expensive and poorly stocked Spar within walking distance (£2 for 2l milk).
Granted, I have a normal IQ and education and I don't have mental health problems but I can still feed my family a decent, healthy and varied diet for hardly any money. I really believe that a great deal of the problem is to do with expectations. People expect to eat meat with every meal, perhaps have salmon or whatever and feel disappointed when they don't/can't get it. They look at the kind of food I cook and think that they could never eat that. The harsh fact is that when you have no money, you have to make do and adjust your expectations. I don't allow fussiness in here, I make one meal, if you don't eat it, you don't eat because that's all there is. Kids soon learn that they would rather not be hungry, even the three of mine who have AS know this now.
Cheapest meal I make is probably pasta with caramelised onions, which costs about 25p a portion, followed by things like pasta with chick peas and garlic, baked potatoes with mushy peas, pea dahl with rice, tomato and cheese rice, chick pea and pasta soup, pinto bean chilli, barley mince, savoury bread pudding all of which cost between 40p and 50p a portion.
Soups, potato bakes, fish things made with tinned fish, potato and lentil curry, potato and onion pie, sweet potato quesadillas, sausage risotto, pasties, judicious use of a chicken, spiced cabbage and potatoes, slow braised cabbage pasta with sour cream, all these things cost much less than £1 a head, are tasty, nutritious and easy to make.
For most people, there is no real excuse to eat junk all the time. There are plenty of ways to learn about cheap, seasonal, easy and balanced cooking whether it's from the internet, a cookbook, a community cooking class or even from your neighbours (I've had neighbours come knocking on my door asking me to show them how to cook things.) It just takes a bit of motivation and facing up to circumstances which I understand can be difficult for some people. Surely, though, if you can't feed your kids properly, that should give you a bit of motivation.