And there is too much consensus around saturated fat being involved in both cardiovascular disease and diabetes for me to say animal fats are a good substitute. It's a step in the wrong direction, even. The only thing worse might be palm oil.
I don't get the same feeling from other areas of study. Most physicists seem to agree on pretty much everything besides the super new, cutting edge discoveries. Same with engineers, chemists, etc.. But in nutrition it's the exact opposite. Google "is milk good for you" and you'll get equally convincing arguments for "yes" and "no". And that's the story for almost any nutrition based question.
It seems like the only option for a non-expert like myself is to just kind of wing it and try to eat vegetables and whole grain, and avoid things like sugar. But if there is one area in life that would be worth hyper-optimizing, I'd have to think it would be eating insanely healthy. It just doesn't seem feasible because I'll spend 10 years eating "healthy" only to discover that what I was eating is insanely bad for you.
Why is it so hard to figure out exactly what I should be eating? Especially since billions of us are doing it, and have been doing it for thousands of years.
Part of the problem with nutrition is it's hard to get quality data, like how do you get long-term studies where you can control every aspect of each participant's diet and lifestyle? The best data we have is all over relatively short periods.
Saturated fat is one thing there is strong consensus on.
https://www.heart.org/en/healthy-living/healthy-eating/eat-s...
https://care.diabetesjournals.org/content/41/8/1732
I'll point out that regarding "healthy" fats, what you see in most recommendations is that replacing unhealthy fats with healthy fats improves heart health, not that adding healthy fats improves heart health.
Eating less meat helps, too.
https://academic.oup.com/ajcn/article/110/1/24/5494812
(surprisingly, in this particular study, white meat was about as bad as red meat)
Nutrition "science" is, like all science these days, inherently untrustworthy.
"The case against science is straightforward: much of the scientific literature, perhaps half, may simply be untrue. Afflicted by studies with small sample sizes, tiny effects, invalid exploratory analyses, and flagrant conflicts of interest, together with an obsession for pursuing fashionable trends of dubious importance, science has taken a turn towards darkness."
Richard Horton, current editor of The Lancet.
When it comes to nutritional studies, which are basically impossibly to ethically control, and are most often funded by large agribusiness concerns, and with a huge problem of only publishing studies that agree with a certain incentive set, you not only CAN but SHOULD ignore it all.
And finally, anything that winds up saying meat is bad for you should raise huge amounts of skepticism. Our entire history as a species indicates that we were built for healthy meat. (Obviously notwithstanding garbage, factory-farmed tortured flesh.)
If you're of the mind that you can't make decisions about your health without a bunch of highly-motivated sophists telling you what's right, you should probably take a step back and rethink.
There are a lot of bunk studies, but that doesn't mean you should ignore all scientific studies altogether. If you have multiple randomized controlled trials with good sample sizes saying certain things, and funded by public health institutions, I want to pay attention to those.
You're right about the agricultural industry and its influence. The beef, chicken, and dairy industries are chief among them.
The animal fats I eat are from my own farm, processed by me, lard rendered by me. I realize not everyone can do this, but quality control (and lack of preservatives and other bullshit) is much easier to do when you're the one doing the cooking.
Just like roasting a chicken yourself is making "processed food", there's a big difference between that and, say, getting some chicken from Chili's, or some canned whole chicken.
When I speak of "processed foods" I guess what I mean is highly processed foods, usually processed in factories, surrounded by incentive structures directly opposed to healthful food production (because it's invariably more expensive).