In the same vein, I highly recommend people try cutting out grains for 40 days. If you're like me, you may very quickly feel so drastically better that going back to grain-eating would be out of the question.

Don't get me wrong: many people do just fine on grains. But some non-negligible percent of people live with a low-level general malaise without even knowing that it's not normal. I know I did for years.