Periods of time I’ve spent consuming very low calories on a daily basis and not feeling as tired as I should feel after only 5 hours sleep a night. Makes me wonder if the less I eat the less sleep I need? Can anyone relate?
There are some theories that it is caused by an increase in adrenaline while fasting. Definitely a thing, try to go for a walk in the evening, work on easing into your bed time. If you are not negatively affected though not too much to worry about.