When consuming bowled foods with more then one in the stack it will consume the whole stack of soup/stew leaving the player with one empty bowl. Foods effected are bowled foods such as suspicious stew, beetroot soup, mushroom stew, and rabbit stew.

So if you set the max stack size of rabbit stew to say 4 and give yourself 4 rabbit stews. Then put them all in one stack. upon consuming 1 you will be left with 1 empty bowl and the other 3 stews are no where to be found.

To recreate the unfortunate scenario execute the following command and consume a stew.  (Insure you are in survival mode as creative will not consume the item)

/give @a minecraft:rabbit_stew[minecraft:food=\{"nutrition": 1, "saturation_modifier":1, "can_always_eat": true}, minecraft:max_stack_size=4] 4

You also won't receive a bowl unless its the last one in the slot

Side note milk buckets do not consume the whole stack however you also don't get a bucket unless its the only one in the stack.