I think bodies are not meant to always be processing food. We are designed for downtime to process the backlog. The body would get to nagging issues if given opportunity to do so.
I also think this has a lot to do with our cancer rates.
I'd say that a less fraught way of putting this is that we have adapted to feast-and-famine since that was the ancestral condition of the species.
So I agree with you that, at least for me, eating less than I want to (or nothing) much of the time, and eating a lot occasionally, feels better than constantly feeding myself more calories (carbs especially!) than I need.
But most people on this site, myself included, don't think we were 'designed' at all.
I also think this has a lot to do with our cancer rates.