I don't know about that, it it looking more like Alcohol is heading down the path of cigarettes where the more unbiased funding and studies that are done, the worse it appears. There have been several convincing reviews[1] recently that showed an increased risk of cancer at any dosage.
[1] https://pubmed.ncbi.nlm.nih.gov/32584303/ (First one I could find easily again)
You can look at dietary recommendations from the 70s, and they’re fine. Eat your plants and don’t eat garbage. The food pyramid was more a product of lobbying than science. The doctors advice wasn't that bad, although there would be less knowledge of the dangers of refined carbs.
People want it to be true that the doctors don’t know what they’re doing, but it’s not (or these are bad examples of).
Granted, I do agree that the science actually hasn't changed that much, and that doctors who do research know ath they're talking about, but your average MD is pretty clueless about nutrition and fitness because that's really not a subject that gets priority in med school. There are even doctors today who still give advice along the lines of the Food Pyramid and My Plate. I've heard more than one account in my social circles of doctors telling people the myth that dietary fat flows freely through your blood vessels and clogs them exactly the same way that bacon grease can clog drain pipes.
> People want it to be true that the doctors don’t know what they’re doing
Also, the root of this statement is something I am surprised by. People want their doctors to not know what they're doing? In what universe is that true? Maybe that fits your experience, but this is a phenomenon I've never encountered in the slightest.
No, you're right, people who go to a doctor certainly don't want their individual physician to be incompetent. I believe parent was talking about a less specific, somewhat "anti-establishment" point of view. Folks who feel that they've been failed by medical doctors, for example -- a chronic condition that they can't get help with. Or people who have other reasons to believe that the medical profession is ossified, or beholden to interests that don't serve patients -- critiques of that sort.
You'll probably see more of these attitudes on the right, but the idea that doctors don't know what they're talking about, and change their recommendations all the time is incredibly popular. So it's not like 100% of people, or probably not even 95%, but I think it's more than eg. 30-40%.
You say they’re clueless on fitness and nutrition, but I don’t know what information they should be expected to know. Your talking about topics riddled with bullshit, when you look at public discourse.
Honestly, there’s not much to know other than to eat food that’s pretty famously healthy (plants), and avoid sugars. Now they definitely want you to limit meat, excessive fats, and refined carbs, too; but the basics are really simple.
There’s lots of studies out there, but there seems to be very little that’s clear other than those basic guidelines. You can really run around in circles with how complex this subject is, yet ignore the basics.