I'd be interested to know what is classed as 'poorer families', I don't earn a great income and have a growing family. I choose my food shopping wisely, and ensure that good nutrition is my priority.
The article suggests that vegetables are three times more expensive than processed foods, but these foods fill people up for longer, which means an overall reduction in food.
If I gave my children a pizza for tea, they would be hungry 2 - 3 hours later. But if I gave them mash, peas, carrots and sausages they would stay fuller for longer.
The problem with processed food is that it is not satisfying, leading kids to pester for more food or pick on junk.