Popular and consensus opinions in nutrition (including those ostensibly backed by science) are overturned all the time. Just look at historical views on saturated fat, GI, cholesterol, etc. etc. That's why the seemingly anti-intellectual advice of "eat a variety of foods in moderation" is actually quite good advice.
I think a lot of the heart disease confusion stemmed from preventing it is very different than what should be done once you have it. I still see a lot of confusion on this in literature. The layman seems to be unaware of it altogether. That makes even legitimate research look very contradictory.
> That's why the seemingly anti-intellectual advice of "eat a variety of foods in moderation" is actually quite good advice.
That is because it is vague, imprecise and can be defined whichever way you want.
For example, how much protein should a person intake? 56 gms per day as per the CDC. Other variant figures in the body building community include like 0.68 gms per kg to 2.5 gms per kg. So which figure does one use to establish the definition of moderation? Genetic and cultural differences also come into play. I have lived in cultures (Africa/Asia) where protein is expensive, eaten less. If I went with that sociological perspective of moderation, I could very easily eat less than the 56 gms of the CDC requirement. If I went with the American concept of protein, which sub population do I go with? Do I go with the traditional American eat a Burger + Mashed Potatoes erry day deal or go all Keto and eat Bacon every day?
Personally, I believe that one should gradually evolve towards a lifestyle that is suited to one's own needs.
It's true that the concept of moderation doesn't prescribe specific targets. It only excludes extreme targets.
The two rules that you really can bank on are that calorie intake is directly linked to weight loss/gain, and you need a certain amount of protein and fat to maintain or build muscle. That being said, protein needed for survival is minimal. Other dietary parameters will affect long-term health, but laypersons are so inundated with misinformation that it's better to eat a variety of foods in moderation than to adopt extreme diets or novel nutritional theories.
Why are those "one weird trick" ads so profitable?
I have a hypothesis that people focus on magic pills (like fish oil) and conspiracy theories (like sugar toxicity) because it is a welcome distraction from an ugly truth: that in order to achieve their ideal body composition, they just need to be extremely disciplined and hardworking in their dietary and exercise habits, and for the sake of long-term health, they should lay off the junk food. There's no "trick". People already generally know what they have to do, but they pretend to themselves that they don't, because if they know what they have to do and fail to do it, that's indicative of personal weakness. It's cognitive dissonance.
> Personally, I believe that one should gradually evolve towards a lifestyle that is suited to one's own needs.
Learning to live your own life really is a lot of work. Everyone's body is different and has its own set of quirks. I wonder when in the future medicine will be tailored to each individual. I would not be surprised if a diet/lifestyle that is healthy for one person is terrible for another. This is obviously the case for some people with well known disorders, but it might be true across the entire population.
For example, if I follow a diet where most of my calories come from carbohydrates, I tend to get very hungry in between meals. And even worse, if I miss a meal I feel very faint. However, if I get most of my calories from fat and protein, I do not get hungry between meals and if I miss a meal I don't feel like I'm going to die.
