Judging from the skeletons they left, our hunter-gatherer ancestors were healthy without need to pay much attention to diet beyond doing their best to get enough.

In particular, they had no difficulty getting enough fiber: there was plenty in everything. Our problem is that our whole food-industrial complex is devoted to stripping out and discarding the fiber we need.

If 40% of Americans didn't brush their teeth or bathe, we would have a hygiene problem of a magnitude commensurate with our health problem.