Maybe the “click” you’re looking for is your choice to allow the desire to be unsatisfied? That is the choice, really: do I satisfy this desire or do I accept the unsatisfied feeling?
When you’re in the car alone, you stop to buy something in the supermarket, so I suggest you “make your choices in the shops”. In a very real sense, you make your choice to eat something when you buy it.
Maybe you don’t need to stop, park the car and enter the shop. Just know that you can do that, and if you do, you’ll eat it.