Man, I was going to go to bed but saw this post and read through all of the posts and had to get up and add a nuance that I think hasn't been brought up yet.
Speaking just on lower-income bracket households:
For families, if you're in lower income brackets, where you are trying to maximize the amount of calories you can get, food choice matters. This is important because the highest calorically heavy foods often lie within processed foods (sweets / carb-heavy foods) etc.
Now, a nuance that I learned from my public health PhD /MD friend: taste buds and the acclimation to certain types of foods might often take multiple (I want to say at least 7, but I'm not too sure anymore) consumption times before they can be accepted. As an example, at first taste of some vegetable, you might find it quite repulsive. After having tasted it a couple of times though, you realize more nuance to the flavor and really like it.
Why is this important? If you're in lower income households, you cannot afford for your child to hate some food and refuse to eat it. The "smart" move is to go for the foods that your family is guaranteed to eat no matter what. Even if you try and make a conscious decision to "eat healthy," the tendency is to revert back to "shitty" foods because ultimately the risk of children/other members of the family rejecting to eat health alternatives is too high. This, of course, leads to a crazy cycle in which you program individuals to consume shitty processed foods, and when they raise children, they operate on the same type of logic with their children.
Self control in this situation/context doesn't apply at all. Maybe everyone else can exercise this "self control" and find avenues to eat healthier and whatever, but this leaves the most vulnerable segments of society at even higher risk.
