I typically do OMAD like 3/7 days a week, then 18:6 here and there. but if I do it for more than like two days in a row I really start to struggle with falling asleep and staying asleep. Like even after I eat my dinner my stomach is just growling. I’m going to try to eat mostly protein and less carbs and see if that helps.
A factor can be sugars depending on exact diet. When you fast, you start running off of a bit more fat than sugar…amplified if you go low carb. If you run a low insulin, orexin levels can increase…and make it hard to sleep