This idea interests me as I have just realized that my insomnia (approx 25 years now) is worsened by sugar. I cut out sugars including "healthy" foods such as prunes, apricots and immediately my sleep markedly improved. But it only lasted a week and it became poor again. I don't know what is going on but whatever it is I don't doubt that it relates to POIS. It always amazed me that things like blueberries, Pepto Bismol and taurine help people, showing an obvious connection to the gut. Now I realize that my insomnia might be due to the same underlying condition. Gut dysbiosis? inflammation? (perhaps, BJim), I have no clue. I am going to experiment with no sugar/ low carbs, post-noontime and then totally abstain.