What do we know about nutrition?

I've done way too much research about nutrition. I listened to actual dieticians and read papers, but also randos on Reddit. After all this time spent I've come up with 2 things:

1. Everyone's "ideal" diet is different. Everyone's body, nutritional needs are surprisingly different. What works for one person won't work for another.

2. Most people seem to benefit from: eat whole (minimally processed, https://www.verywellfit.com/what-is-a-whole-foods-diet-22419...) foods, 2-4 times a day, eat to satiety but don't binge, exercise for at least 60min/day moderate intensity, treat yourself but only occasionally, visit your doctor and get lab work done regularly. General, boring advice you will hear from almost everyone, but it works. At least for most people, see 1)

There are some facts, but not as many as most people think.

Many people have religious views with a nutrition component, and some will try latch onto any study that supports their view and push it while ignoring others that don't support it. Some will even go so far as to design a study to provide the results they want. Vegetarians are the most obvious example of this, but there are others.

Nutrition is hard to study even when you want to do the right thing. Most effects are small and so it takes a long time for anything to be measurable. People tend to be unable to stick to their assigned diet long enough for a controlled study to get real data. (the exceptions are confined to a hospital bed or prison cell - both of which add confounding factors that mean the study won't apply to normal people)

Attempts are made to work around the above with surveys. However people are bad at remembering what they ate yesterday, and tend to lie to make themselves seem "healthier" than they really are. As always when doing a survey it is hard to separate confounding factors - the big on in this case is people who smoke also eat what is considered a less healthy diet and so it is hard to figure if the diet is really less healthy, or just another bad effect of smoking.

That said, there is some good science out there. I don't know how to find it, but there are nutritionists who know statistics and are making real attempts to separate the above confounders to find a truth. They tend to not get a lot of press though: since most of what they discover is small effects it won't generate headlines, while someone who doesn't take care can easily cherry-pick something and extrapolate far beyond reason to claim another miracle diet that will add 10 years to your life (or something else that diet will never do)

The one thing pretty much every school of thought from carnivore to vegan agree on. Too much sugar is bad.

My guess: nutrition is probably like physics, we know a hell of a lot but just not everything.

My dream is one day we will reverse engineer the human body completely, no more mysteries with the ability to recreate any part of it seamlessly if it ages or is injured.

I think living by this is a good basis: Eat food, not too much, mostly plants

We know that vegetables are good for you. Processed food is not so good for you. We also know that eating too much causes problems.

We know that we need nutritionally rich food to stay alive and healthy. My wife builds nutritionanalyzer.app to achieve this

Other than apparently being extremely boring, Huel seems to cover all the essentials. Other meal replacements are available.