Give Cavemen a benefit to how nutrition works. Since they are used to a “feast or famine” lifestyle, they should never choke on food, and just stop eating at their upper limit. Possibly, the upper limit is even increased so if they eat a lot, they can go for longer without getting hungry (or, conversely, slow the nutrition clock when they are hungry so they take longer to get to Weak/Fainting status). Also, they should never get “Blecch!” rotten food effects since they are adapted to eat food that isn’t in the best condition.