I skimmed the article. I think the point is that the food banks distribute, together with the goods, recipes that encourage poor eating habits. That recipe for cottage pie made with tinned ingredients and powdered mashed potato sounds revolting.
I fed us last night on a £3 Co-op meal deal - packet of stirfry veg, noodles, and fresh green Thai sauce, plus a tub of fresh mussel meat (£1). Not because I am economising, just because I fancied the mussels (and I was a bit lazy, I usually cut my own stirfry veg). There were leftovers. The man who sells flowers outside our station also sells fruit really cheaply (30p for an apple). So there is healthy cheap food available, if you don't want to eat tinned food. Unless of course you have absolutely no money at all.
But the point is food banks should not "erode human health" - as the article says, that is completely counter-productive. I like the other schemes mentioned, e.g. The Felix Project.