I wasn't talking food allergies and health issues, I was talking about people wanting to pick and choose during a survival situation,
There is interesting psychology surrounding people and food. Allergies aside. You need look no further than the vast array of eating disorders in western society, and top that off with people wanting to try and exert some form of control (choice of food) when a stressful situation, and I suspect there will be some interesting outcomes.
To draw from TV experiences, often in the first day or two people can be a little relaxed, even fussy, about food, but when hunger kicks in and food runs out the situation does change. For example in The Colony(s) they start to catch rats, eat cat food (at least one person anyway), and cockroaches … something which could not have happened on day two no matter what the situation was.
I always remember seeing an interview with a bushman (in Africa) and he was asked what was the most important skill for a hunter, his one word reply “Hunger”.
When the food runs out and we get hungry, we slowly realize that anything edible becomes fair game and even the inedible can be an option. I refer you to some of the early Arctic explorers like USS Jeannette where the crew boiled and ate leather, and even more grim: the fate of The Whale-Ship Essex (on which Moby Disk is loosely based) where the crew were drift in lifeboats for many weeks …
Hey I’m not advocating anything here, just pointing out that being fussy about food is a luxury which most of us can afford; given limited options we can all adapt (allergies permitting); given desperation, anything is possible.