I find it tricky to talk about food because I tend to have quite strong views and it's easy to come across as pious when - just as @Wingingit11 says - I clearly haven't always managed to maintain a perfect diet or I wouldn't be here!
I regard myself in an idealised way as someone who eats really healthily. I've been vegetarian all my adult life, I genuinely like lentils and whole foods, don't have a particularly sweet tooth, try to buy organic, I cook from scratch blah blah blah. I think if I'd been this person all my life I'd probably have overeaten because I love food, and I might have tended to be a bit overweight at times, but I don't think I'd be obese.
However, there's this other part of me that also picked up all sorts of damaging ideas and compulsions about food from family life (like sweets being the ultimate reward but getting fat being the ultimate sin), general dietary advice of the past that didn't suit me (when I was young it was all eat lots of carbs and low fat) and the increasing introduction of UPFs. I do feel very strongly that although obesity is complex and varied, that UPFs play a massive role. In every country where they're introduced you see a huge increase in obesity. They're specially designed to be compulsive and make you want to eat more. Obviously eating the odd thing doesn't do too much harm, but it's hard to stop at the odd thing.
I've had huge periods of my life where I've eaten loads of this type of crap really quite compulsively and it took me years to think maybe it was the food having this effect on me rather than me being too shit to control myself in relation to food. I feel so much better without it. I know there are lots of people for whom it's not an issue, but I think some people are more susceptible to it - possibly physically, but maybe also because of having a somewhat compulsive personality. I'm an ex-smoker who also used to drink a lot too, so I'm definitely that way inclined. I don't think half the population have become lazy and greedy. But when I see someone using MJ and eating tiny amounts of crap food, I want to stage an intervention and plead with them - not in a shaming way, but in a be kind to yourself way. This is probably me projecting as there are lots of times when I needed to do that intervention on myself and failed.