What NO thats not how fridges work you stupid fuck, what the fuck?
Cooling is INCREDIBLY efficient, it costs basically nothing to MAINTAIN a temperature. If anything it would cost LESS electricity to keep a bunch in it, because of something called thermal mass. Basically, more cold stuff means everything stays cooler for longer. This is also particularly important for fridges, as when you open one all the cold air falls out. If you have an empty fridge, that means almost ALL the cold has fallen out. If you have a full fridge, that means most of the cold is in the stuff in the fridge.
Imagine an ice chest full of ice with one soda can, and another with no ice and one soda can. Which soda gets *warm* first? The one with no ice.
In a fridge the food is the ice. It's not as cold, but it still IS cold.
Speaking of ice chests, if you want to save power, get one of those. Cold air sinks, so when you take the top off an ice chest, wheres the cold air go? Nowhere! It can't go through the walls, and it won't rise from the top, so opening it is basically free.
And on top of THAT, ELECTRICITY IS CHEAP YOU'RE NOT SO POOR THAT THIS WOULD ACTUALLY SAVE ANY MONEY AT ALL