I think you've raised an interesting point, and I'm interested in objective discussion.
There's often a tendency for low income families to opt for cheaper convenience foods, say they can't afford to diet because fresh fruit and salad vegetables are too expensive. I believe they're wrong, but it comes back to education, both at school and in the home, and as you say many of the cheaper foods that are readily available and promoted in supermarkets are high in unhealthy ingredients and additives. I make a choice now to eat meat that has been humanely reared, eggs from free range chickens, avoid transfats .. but they cost more than the other options. I eat less meat as a result, but I am also in the fortunate position that I can afford better quality food and do not have to feed a family, and I know how to cook and make the best of what I buy. There's a generation now, many of whom don't know how to do this .. they never learned to, and should not imo be dismissed as lazy, stupid etc They had the education and upbringing they were given. We're not born feckless, stupid, lazy .. we are a product of our upbringing and schooling.
It is possible to eat healthily on a low budget. When I was a student 6 of us shared an old terraced house in the East end of London; no bathroom and an outside loo
We had very little money, but we ate healthily. You can provide a nourishing and satisfying stew with cheap vegetables and a small amount of meat or offal .. even an Oxo cube instead of the meat. We even had a cooked breakfast every morning, whether it was an egg, or baked beans on toast. And ox liver was a regular feature on our menu. Casseroled with veg it made a wonderfully rich and tasty meal .. although the texture was like old boot leathers ..
But we'd all learned to cook at home from mothers who remembered rationing and food shortages. We had no biscuits, sweets, potato chips etc in the house; they weren't in the budget. Cake was a treat and was made from scratch.
Years later when I had my daughter and as a single mother took unpaid leave for the first 6 months of her life, I as on benefits. After rent, bills etc there was not much left over, but I went back to shopping at street markets, buying the cheapest cuts of meat, picking up things on their sell-by date which were reduced (which I still do today!) etc. It can be done, but if you don't know how to do it it's hard. I've seen families in the poverty trap on benefits buying individual meat pies and frozen chips whilst saying they can't afford to buy healthy food, yet they could cook a healthy meal from scratch for the same money ... if they knew how. They're not all lazy or spongers .. just not educated in how to shop cheaply and cook healthy meals. But living on benefit isn't easy, and generally you don't have much money imo.
Jamie Oliver has changed the way school meals are provided here (he's currently attempting the same thing in the USA), often fighting parents who are keener on their children's "rights" to eat fried foods that they are about their health .. ignorance through poor education again imo. Fact; he needed more money to be spent on the food budget to provide good, healthy food that would attract the kids. Imo that's because kids now grow up in a world where expectations are different, and they expect choice, and the meals have to be really appealing. Not saying that's a good thing, but it's what is .. and to effect change you have to work with what is, not just shout at people, or dismiss them as lazy
But if this generation learn to enjoy healthier foods, and are educated on how to do this cheaply, things can change and improve.
A friend of mine had to bring up her family on benefits or low pay for several years. And neither she nor her husband were "lazy gits". Her husband was made redundant during a depression; there were few jobs, he worked when he could, taking jobs that were menial and low paid. They had 4 children, who all needed clothes; she made them. She scoured the markets, still fed her family well, although cheaply. But it was difficult. One daughter was musically gifted .. and as she said "A clarinet doesn't stew up well!" But she too had learned how to put food on the table cheaply from her mother. If you've never been shown how to make a pie from scratch, perhaps never eaten one, it's all too easy to believe the only way is to buy one .. in which case when you have little money you'll turn to the cheapest but worst processed and unhealthy pie to put on the table. But her children learned from her, and when times have been tough they have been able to feed their families well. It's a circle which can be vicious and downward spiralling, or positive and improving.
You can buy a turkey leg for £3 and it will feed a family of 6 for Sunday lunch, albeit frugally .. but you need the education to understand that, and for many years our "domestic science" classes in schools concentrated on making sponge cakes etc rather on how to feed a family nutritious meals on a shoestring. Change needs to happen; it won't happen overnight, but it can start.
And yes, I'm sure some of the people dumpster diving also smoke or drink cheap booze, or may be on drugs. True, some may be homeless because of drink or drugs; but some are not and turn to these options because of the life they've been cast into. Again, not an excuse, but a reason. To be made homeless is an incredible blow to one's ability to act with intelligence. Living in a hostel or bedsit is hardly conducive to taking responsibility for feeding yourself or your family properly; and many people are becoming homeless because of the economy downturn. I do not dismiss them all as scroungers.
Caryl