Per this, Ramadan fasting is 13-15 hours per day: https://www.brandeis.edu/spiritual-life/resources/guide-to-o...

Since the non-fasting hours include a night of sleep, that schedule sounds pretty rigorous to me. Americans typically have an eating window of 12-15 hours, eating 5 times per day: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8705992/