Correct me if I'm wrong, but in an ideal situation, cortisol would rise upon waking (making you alert) and leptin would lower upon waking (making you hungry.) Does this mean that people that aren't hungry in the morning and intermittent fast have a hormonal imbalance/faulty circadian rythm?

Perhaps if stress is REALLY low, intermittent fasting in the morning isn't that big of a deal, but not consistently. If healthy, we should posess that "metabolic flexibility", but on an everyday basis I feel like that may interrupt the body's natural hormonal behavior.

Has anybody (particular females) noticed any differences with long-term fasting vs. when they weren't?