People experiencing low income in the US aren't generally just low on money. They're also low on time, energy, and often infrastructure. It's hard to buy staples in bulk and cook healthy meals with them when you don't have the time required or a place where you can reliably and safely store the staples.
And, at this point, a lot of it is cultural. Not all people value healthy food.
It seems in the US eating well is less valued than some places. Not sure why. This seems to propagate through generations, i.e people growing up around fast food and prepared food don't place value or learn to cook.
Also (and this is probably an "insensitive" opinion) yes, sometimes people really are too stressed and busy to properly prepare food. Other times (perhaps more frequently) they are just too lazy.
I think there's a glimmer of truth to this. And it's not that people are lazy because they're bad people. It's because the situation you're in is soul sucking. It's horrible. Imagine every day of your life living knowing that you may not be able to make the electric bill, pay your medical bills, worry about missing work or any of a million tiny little things that make life harder when you're poor.
Then convince someone that they need to spend an hour cooking healthier foods that requires more effort for most likely no benefit. Being in that position, I thought that a lot. It was easier to get McDonalds and then sit down in front of the TV/Computer and distract myself from the problems.
I think the problem isn't that people are lazy, that's a symptom of the real causes: anxiety, depression, and their ilk; from being in a situation that makes it all too easy to nest inside of and accept.
People experiencing low income in the US aren't generally just low on money. They're also low on time, energy, and often infrastructure. It's hard to buy staples in bulk and cook healthy meals with them when you don't have the time required or a place where you can reliably and safely store the staples.
And, at this point, a lot of it is cultural. Not all people value healthy food.