The following is my personal opinion and should be read as such. Thanks in advance.
Me and a handful of friends started a realm, long time players since alpha days. We all came to after a few months playing hard mode survival, that the hunger system really needs a rework. In it's current state its really a chore you have a bar with 10 meat and all but 2 are useless. It doesn't really add any layers of challenge or fun its just an annoyance that you constantly deal with.
And another sad part there is a huge variety of food items in minecraft but it doesn't matter because most of them aren't stackable and require many materials to create, but yet they under perform most stackable food items. So you end up basically eating meat and bread or a similar combo. Alternating when needed.
I would propose that the hunger bar be divided into a range of health regeneration depending on fullness. The negative side affects of no sprint at 6 and below and taking damage at 0 are fine, but ranges 6 to 17 don't do anything so there is plenty of room to add it in.