Like when you eat raw food in vanilla there is a chance to trigger the hunger effect. Maybe ether just a line for raw true or false default to false or a way to add a potion effect to the eater with a % chance setting.

Apparently only chicken does this, never new that xD but the effect is Hunger for 30 seconds (30% chance).

I actually came here looking for how to add a potion effect to food items.
I see there is the IItemRightClick function and that might(?) work for my purpose but I have no idea if that consumes the item that is right clicked.

Is there an example of anyone successfully adding an item/food item via ContentTweaker that applies a potion effect when the player consumes or right clicks with it?

I think it would be better to allow for foods to apply potion effects in general and add a probability function to it. i.e. you could apply a hunger effect but also other effects like regeneration etc.