Basically, instead of/in addition to food granting a temporary regeneration effect (that gets canceled on damage), simply being at full food grants a health regen buff similar to the Vitality 30 passive bonus.
This would have the same effect over long fights as the current health bonus, while allowing food to be used more efficiently to reduce hunger, instead of as makeshift healing items. (Not that food is particularly scarce in this game, but that’s another matter.)
As a bonus, this would be less confusing to players who see their hp appear to drop when they eat food when it is actually their max hp being raised.
Maybe with this change, the survival attribute would become more useful in and of itself, by keeping the player at max food for longer, or by changing it so it boosts the full food regen effect.