If you are almost dying and died while eating something while KeepInventory is on, you will still be able to continue eating, you will lose 1 of your food items and your hunger will be filled.
Eating... Dying, inventory kept. Continue eating (before respawn)  hunger level filled according to what you ate, and you lost one of your food as you used it. So you just waste an item when you died. (While you are dead)
Including the sound made when you eat and the gear equipped will play while you are dead.

Also everything can be seen in the following video: https://youtu.be/C6_4exnUUb4

So first, I tried doing it while keep inventory was false, then when it was true.
You can also see that I gained golden apple effects after dying. And hunger effect also removed what I gained from the apple, you can see that.