A variety of healthier foods are expensive though and to give a decent range and variety of flavours etc will work out more expensive. Yes, some health food is reasonably priced but then you'd end up having the same stuff over and over again which is hardly healthy.
There is also the time component. A working family is very short on time and this is an important part of it. However, I think a number of the families at the extreme ends of the spectrum are not really limited by these problems. It is the families that 'cope' that are faced with and overcome these challenges.
Lies, it's all lies - why are we peddling this myth that nutrition costs too much or takes too long?
I am single, do all my own shopping, cooking, housework, work long (10 hour+ days) and I have no trouble.
My food bill is about £25 a week, it isn't expensive and it doesn't take long to create a few simple and nutritious meals and keep the stuff in to make them.
I regularly cook a curry at the weekend, all I do is buy frozen veg, chicken breast, onions, a jar of curry sauce, fresh chillies and a tin of tomatoes - chuck in a casserole dish for 4 hours while I'm busy on Sunday and I have dinner for the rest of the week. Cheap, and prep time is next to zero - making it or re-heating it in the week.
If I don't do that I'll buy in some chops, chicken breasts or frozen fish (bought fresh or frozen they go in the freezer, so I can choose when to eat them). Meat/fish goes in the oven in foil with a few new potatoes on the tray, frozen veg goes in the microwave. Takes longer to cook (45 mins) but I can do other things while I wait, it doesn't need watching.
Breakfast is always instant porridge pots, no time, no mess, not really expensive - but equally you could save £5 a week buying oats. Lunch is always some herby salad, rice and a piece of fish/chicken - not expensive - not hard to prepare.
Or I could accept the dogma that good food costs too much and takes too much time and buy sandwiches from the van, macdonalds for lunch, and chips for tea. Cost myself a fortune and send me to an early grave.
Madness.