No, "diet and exercise" is not the only recommendation. I don't even know what point you're trying to make there - if that were the only recommendation, health care costs would be fairly low.

And it's not just mental health issues (~25% of all chronic health issues), it's also respiratory issues (~10%).

Then add to that the fact that many metabolic diseases have long lists of causes that amount to "not really sure". Atherosclerosis? Can be caused by physical activity. Hypertension? Being older than 65 is a cause.

What the Rand paper does say is "90% of all health care cost is incurred by people with at least one chronic condition". Not metabolic diseases. What it also doesn't say is that the entire 90% are attributable to chronic diseases. (It's sort of akin to claiming that 10% of all healthcare costs are incurred by people named John, Robert, or James. True, but certainly not causal)

Again, I'm not saying that chronic diseases aren't contributing a huge cost burden. I am saying that they're far from the only cause of the cost burden, and that blaming it on metabolic diseases is highly misleading even if you just focus on chronic diseases.

Thank you for bringing this up. The medical community's intense obsession with people's size and shape over their health causes a lot of misleading conclusions and misguided efforts.

If you walk into the doctor's office underweight and concerned about an issue you're having, the doctor doesn't put you on a strict fettuccine Alfredo and hamburger diet before treating you.

If you're overweight and concerned about an issue, you're far more likely to be told to lose weight and ignored.