Why some people can't feel satisfied without eating meat

Answer 1

This is a fun question!

So the answer comes down to the hormones that regulate hunger and satiety. The main one that regulates satiety after eating is cholecystokinin (CCK). CCK is released when protein and fat enter the small intestine. Its job is to stimulate the release of other hormones that help with the digestion of protein, fat, and also triggers the brain that it's time to stop eating because food has entered the intestines and it's time to rest and digest!

Fat is going to be the strongest stimulant for CCK and protein the second strongest.

https://en.wikipedia.org/wiki/Cholecystokinin