> it's hard to imagine that everyone 50 years ago was just much better about dieting and counting calories?

Do we just have a lot more food available now? Not just bad food, but calories of all kinds? Combined with steadily automating nearly all of the hard work, I'm not surprised people get fatter these days than 50 years ago. I bet the average person today is actually much more aware of what healthy eating looks like, it's just that there aren't that many really physical jobs anymore and food is extremely cheap and plentiful for most.

Snacking (defined as between-meal eating) has had a massive uptrend (in the USA) since the 1970s:

https://pmc.ncbi.nlm.nih.gov/articles/PMC10097271/#:~:text=S...

It's really closer to 70 years ago to see the roots of the obesity epidemic in the US and had a lot to do with the post war world. To put it in another way, machines have taken over the vast majority of labor. Even people that do 'hard' jobs are still using a ton of tools that decrease the amount of physical effort they put in the job. Add in we converted the country from a human oriented place to one where cars rule, all while increasing the ease of consumption and we now have an epidemic.

It also coincides with the rise of manufactured foods available for incredibly cheap prices. And the average percentage of a monthly budget spent on food going down.

Basically incredibly tasty food became plentiful and cheap and convenient right when physical labor went away.