I came across Fire Your Doctor! How to Be Independently Healthy by Andrew Saul while searching for info on natural hygiene, mentioned in a comment. I liked this story:
I had acne . . . It peaked when I was seventeen. . . Then I went overseas to study, was more than a bit stressed, and took my already considerable chocolate, sugar, meat, and greasy-food eating habits to new heights. My broken-out skin broke out still worse. Eventually, having failed to see any improvement otherwise, I changed my diet, and the acne went away.
Of course I support this non-gatekeeper approach to health. What about the book? Pro: Well-written, a reasonable amount of evidence. Con: No discussion of actual cases. What actually happens when you treat problems this way (often with vitamins and other supplements) is very important to know.
I found nothing about fermented foods, omega-3, or sleep (neither sleep problems nor the value of sleep for health). This isn’t really a weakness of the book, which is about a certain way of doing things; it’s a weakness of the way of doing things.
pg 168: Sleep Disorders
the Afterword starts on pg 169 so don’t much.