You go back 50+ years ago and you didn’t have teenage girls being pumped full of hormones via birth control pills. Pills that are known to add to weight gain. That was a political push to "end teenage pregnancy".

You go back 50+ years and you didn’t have a fast food culture supplied by animals also pumped full of hormones to make them grow and put on weight faster to fill that need.

You go back 50+ years ago and our wheat based diet was filled by a different, unmodified variety of wheat with a lower glycemic index that digested differently in the body. The change was made to increase yields and deal with various blight problems.

You go back 50+ years before the advent of diet culture and you didn’t have people setting themselves up on that diet roller coaster, again in YOUNG STILL GROWING BODIES, that inevitably lead to a lifetime of weight problems because that’s what starvation does. It triggers your body to put on more weight. All because if marketing propaganda normalizing extreme thinness.

If you go back 50+ years you would likely find lower overall stress hormones in the population at large than you do today because of long term food and financial insecurities as well as the rise of rape culture and the criminalization of youth.

I could go on about how the differences between then and now affects the caloric expenditure side of the equation.

You’re not entirely wrong to say if calories in is more than calories spent then one will be fat. And science is great. I love science. But science isn’t the end all be all.

You have to be careful with science, that you don’t get tunnel vision by ignoring things like history, other factors that might be coming in to play, your own biases while you’re accusing others of bias or victim narrative, etc.

That’s how you end up with things like eugenics and racial comparisons backing up white supremacy. Those were also plain, ‘inarguable’ "science". I put science I’m quotes here because real science stays in its lane. It doesn’t conflate. Real scientists allow for new evidence, new thoughts, new dynamics. They often get quite excited over the prospect of being proven wrong or even not entirely accurate. They’ll nerdgasm right there in front of you; it’s kinda hot. I digress.

In the end, it’s not very good science to compare life from 50+ years ago and today and hold that up as proof of the laziness of "fat" people. It willfully ignores a lot and you just come off sounding like as much as ass as boomers who say young people are lazy because they can’t afford a house in today’s economy. Like it’s the same economy from 50+ years ago. When it’s clearly not.

Please, take the authors advice and be quiet for a while. The world will not end if you listen to others a bit and keep your narrow minded opinions to yourself instead of hogging all the airspace.