This might sound a little funny to some people, but Buddhist monks are actually my role models for OMAD. I’m a practicing Buddhist and aspire to be a monk someday (maybe not for life, but at least for a couple of years), and one of the precepts that monks keep is to not eat after 12:00 PM. They basically do OMAD with a morning eating window, and the rest of the day they can only have liquids like water or unsweetened tea and coffee.
For them it’s a practice of non-attachment to food, but for us regular folk it’s just a diet!