I do wish we could just buckle down and figure out diet and exercise related health knowledge. So many diet and exercise related studies just have too small sample sizes and are too narrow. This makes sense because it’s expensive and time consuming to track a lot of people’s diet and exercise routines to get rigorous results. I think, however, we should just bite the bullet and pay $10 billion (or however much) to precisely track several thousand people’s diet, exercise, sleep, etc and figure this out. Basically pay people as a full time job to eat and do what you tell them (ethically of course. They aren’t slaves. We just need better data than sample sizes of twenty people trying to track their own health with self reported diaries).

Most of what we need to know, for most of the population, we already know.

Even if the effort you suggested were to be done, the noise would continue to distract in exactly the same way.

I've worked as a tech exec, and I've worked as a personal trainer, and I've competed... we have the knowledge. We know how people can be healthy, we know how people can live long lives, and we know how people can have bodies that are a benefit to their lifetimes, not a burden.

I remember a study, it graphed a demographic of people across a scale from "healthy" to "unhealthy". What they found was that people were heavily represented on either end of the scale, but to a significant degree, not at all in between.

So, the choice is... people's (barring economics, to some degree, I'll concede -- though, being poor in other countries isn't the health catastrophe that it can be in some first world countries).

Yup, there's a lot of information that can seem to point in contradictory directions, but you get some very, very clear signal out of it in a couple of important directions.

People still seem pretty resistant to simple interventions like this though. I think a big part of it is that most people have an incredibly powerful status quo bias, and get extremely uneasy with diverging from the norm of behavior they see around them (even if those norms are of generally far worse health than they're targeting).

I've spent the last decade incrementally understanding more about nutrition and optimizing my diet, and I've reached the point where the divergence between mine and my friends' diets has become pretty insane. Not coincidentally, now that we're starting to enter the period where age catches up with our bodies, I'm by far the healthiest, by both appearance and symptoms. I've had friends ask me what I do, but it's far enough outside the norm that they assume it's impossible or that I have iron willpower (spoiler: I really don't. If you eat healthy, your tastes shift towards healthy food).

This is a general problem with people; in the narrow case, it could be solved by changing their environment (ie blanketing the country with PSAs with simple messages, like we did for smoking). It would do infinitely more good to somehow grant people the intellectual confidence (or indeed, capability) to avoid blunt heuristics like the so-called "wisdom" of crowds, but I have no earthly idea how one would do that.