> the healthcare profession could do the same double-blind studies they do on drugs -- but on substances that are not patentable
But... they do? Pretty much everything you mentioned is well studied, although a lot of times it’s hard to get conclusive evidence when the effect size is small.
Why are only pills, pills with which pharmaceutical companies (and usually doctors, via commission payments) make money, prescribed, and nothing else?
Maybe it's not the Doctors' fault however.
Perhaps the mindset was taught to them via most Medical Colleges and Universities, who accept large amounts of money from big pharma to teach that prevailing, patented-pharmaceutical-drug-centered mindset... and perhaps it was regulated into them by well-meaning, yet exclusionary and limiting government regulations...
I hold Doctors harmless... but they could prescribe less man-made products for profit, and more that are made by nature for free, or pretty close to free...
Again, pretty much everything you mentioned has been studied quite a bit. Yes, even with double blind studies (e.g. [1] to pick one at complete random). Some of the things you mentioned (diet, exercise, sleep) literally have entire subfields of medicine devoted to them.
When the evidence says they help they usually are. Losing weight, sleeping more, prenatal vitamins, etc, are all regularly recommended or prescribed by doctors. But, again, the issue is that most of the time the evidence is either inconclusive or says they don’t help.
But... they do? Pretty much everything you mentioned is well studied, although a lot of times it’s hard to get conclusive evidence when the effect size is small.