The system of how food buffs work should be fixed, centered around being able to utilise the vast amount of buffs that can be given as seamlessly and efficiently as possible without breaking the balance.

Fix 1.
The fix i suggest is to be able to remove ANY food buff you currently have active either by right clicking ontop of the buff itself or adding a button to any of the interface elements that bring up a list of active buffs where you can choose to remove them if you want or need to (this way would be safer from miss clicks and make it easier to to enable removal of other buffs as well).

For balance purposes any food "debuffs" like satiated would still remain so that you cant abuse it.

This would enable players to more easily switch between what they are doing in the game, example: fighting using simple cron meal and switching to fishing using balacs lunchbox instead of having to spend millions more on marvelous balacs lunchbox.

It would also enable players to test out the difference between different grade food buffs and unbuffed without having to wait for the entire duration of the buff to run out.  

Fix 2.

When having a cron meal grade food buff and satiated active and trying to consume any lower grade food that will not get applied there should be a text message popping up saying that you are unable to consume lower grade food while X food and satiated is active, the food you tried to use should also not be consumed.
This fix is simply to stop the wasting of food and silver for players.