My question is this: do you really think your parents really didn't know that sitting around all day eating cookies/treats/soda/etc. will gradually make you fat? And as they saw you getting fat, do you really think they couldn't have known that all that shit must have been a factor there?
Yes, they didn't "know" for all practical purposes, they weren't told and then were thrust out on their own and set with concerns like keeping whatever food on the table they could afford (ie: boxes of govt shit most of the time) or a roof over our heads and trying to enjoy their own youth to some degree, before they had a chance to develop like people from better socio economic backgrounds or with more educated parents. And I dare say I had it better than most poorer people, they werent violent drunks or addicted to anything, they were just too young. The average situation is FAR worse than what I had, both in terms of living conditions and quality of humans.
They certainly had a clue that overeating and sitting around is what helps make you fat, but the real gravitas of it was lost to them, and their entire generation for the most part. Now we're a few generations deep into that, and it's only gotten worse.
It may seem hard to believe if you grew up in a better sort of area and/or are fairly young and educated yourself, but this is how it happens most of the time. This is whats actually out there.
And not all poorer people are fat, its not that one issue that gives me this perspective, its just that when you're poorer, you're far more likely to have underdeveloped surroundings that can have quite a profound effect on your perspective, which is what drives everything in your life.
I totally agree that as an adult its your own responsibility, but taking ownership of it is extremely difficult when you aren't grown with the tools to do so. It was extremely hard for me to do so, requiring many changes in character and approach over long periods of time, and those are the things I try to foster when I try to give advice/help out other people struggling with the same situation.
Circling back to the point of the thread I think education about these things is the only real way to make a difference, not just about the nutrition, but about lifestyle and approach to living in general. Lifestyle has been highjacked by corporations that manipulate the information that gets shoved down peoples throats, literally and metaphorically, to keep them sick, ignorant, and consuming.
Declaring it a disease will likely have a positive effect overall, despite what I may think (my own personal opinion) about using the term disease, but I think much broader strokes can be made, though those would involved harming large corporations quite a bit, which won't happen while they run everything.