I wasn't considered a picky eater at all (and people would comment that I ate my veggies with enthusiasm) but at some point started "refusing" bologna and hot dogs (they made me throw up, as an adult I suspect it was the nitrates??) Also fried food. People thought it was weird to have a kid that would only eat one french fry reluctantly and get teased but not eat any more... My mother threw on a hamburger when the others had hotdogs. Her father had alot of stomach issues so she said I had "his stomach" in a nice way.
Generally as I grew to adulthood I just don't like alot of preservatives/fat people think I'm being snobby or concerned about weight but if I eat something and throw up I'm not having fun and don't care to repeat this, so I avoid. I am still called the one with the [insert surname] stomach and just do what I need to do.
So I guess this is a long-winded way of agreeing with the others that especially if they are willing to go to bed hungry, there might be something physical about it.
Good luck!
