Herbivore Diet Mechanics | Dynamic Gameplay

Soft Diets vs Tough Diets
Grazing, & browsing; trees, bushes, and grass are everywhere but take time to fill hunger. Fruit, berries, fungi, etc are rarer but fill hunger faster.
Soft diets are straightforward, but tough diets incentivized by opening more slots (3 to 5 depending on species?). Slots allow you either to add one extra food source each (some foods would be available only to certain species) or to add species-specific abilities:

Iguanodon heals venom quicker after eating some (but not too many) button mushrooms
Anodontosaurus can extract more water from roots
Stegosaurus flesh slightly poisonous after recently eating poisonous mushrooms
Camptosaurus able to dive for seaweed (low lung capacity)
Struthiomimus runs faster after eating fruit
Etc

I think this would make herbi gameplay more dynamic and unique from carnivores, offering a very different playstyle.
Sorry if any of this has been suggested already!