Just like alcoholism, or any kind of other addictions.
I've struggled with alcohol abuse, and once you come to the realization that you're abusing it, the fix FOR ME was relatively simple: I stopped (under medical supervision) drinking, or to be more precise: I stopped starting to drink. I have no problems not drinking, I have a problem that when I start I cannot stop.
I have the same issue with food. Not eating is a lot easier than stopping to eat. But I cannot completely stop eating.
Yet with alcohol people are like: hey, good for you.
With my weight issues people are like: dude, just eat less, or exercise more.
(I stopped sharing the food story with people).
"Just Eat Less" is roughly the way to lose weight, but the problem is not that fat people are so unbelievably stupid that they didn't know this. I am sure for some people it really is that simple. Not us.
My weight has been a bit of a rollercoaster. I've never been terribly thin, but I've been "not technically obese" from time to time. I'm currently back on the downswing, but God, what a pain in the ass. It feels like gaining weight is incredibly easy and losing it is incredibly hard (and I do believe this is validated by the science, because you wind up with more fat cells when you first gain weight, which I guess is both relieving and terrifying.)
No matter how many attempts it takes to fix my body, I'm obviously going to just keep trying, because obesity is horrible for you in so many ways. It saps your energy, it's carcinogenic, it increases your blood pressure and risk of heart disease, but it feels like one of those struggles that is never-ending. I've improved my diet numerous times but it never feels like it's quite enough.
There's an equal and opposite level of messaging to keep eating, which is less conscious and runs under the radar.
Snacks are literally designed to be addictive. TV ads start from birth. Most restaurants have huge portion sizes. "Family" and "Festival" events assume overeating is expected. Junk food is cheap and quality food is expensive. Overeating is framed as being "naughty" but also indulgent and nurturing.
All of this is a huge social problem that's not acknowledged at all.
It's very, very hard to Just Eat Less when there's a constant barrage of messaging encouraging you to do the opposite, and you're not even aware of it.
The contradictory messaging is actually a classic crazy-making psychological double bind. So of course it's very difficult to make a dent in this, and even harder to permanently change habits so all the contradictions no longer influence you.
ppl keep blaming this, but this is contradicted by shrinkflation, yet people still are getting fatter than ever. There is nothing to stop someone from buying more food to offset smaller portions.