Probably not total bullshit, but I don't think we know enough to say for sure what the best fasting/eating schedule is for everyone.

I've head this guy: https://www.salk.edu/scientist/satchidananda-panda/ on a couple of podcasts, and he seems to be the expert on food and circadian rhythms, so you might want to check out his book. https://www.amazon.com/dp/B07BVF1Z6Z/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1