This issue can occur when eating one food excessively for long periods. I distinctly recall this being covered in pre- college health classes.
A common urban legend was the girl who only ate carrots and turned orange.
the girl who only ate carrots and turned orange.
I can confirm this is a real thing. When I was a kid my step-mother went on this fad diet that involved drinking carrot juice every day. It was this whole production where she bought a juicer and I remember multiple large bags of carrots coming in the house. There was always leftover carrot pulp in the trash, etc. Anyways she went wild with it for a time and sure enough her skin started turning slightly orange, mostly along her forearms where the skin was thin.
That’s when the carrot juice stopped.
So yeah she wasn’t an Oompa Loompa but it was definitely a visible change.
A friend of mine spoke to this man on a train ride. He lived in the town we went to college in.