Does the amount of food in your refrigerator matter in how much it runs?  Does an empty fridge use less energy because there’s nothing in it to cool?  I guess you can take that further and say does the contents of the fridge make a difference.  Does a fridge full of liquids require more energy than a fridge full of fruit?  I guess it all comes down to how much energy does it take to cool air…If I were to make a prediction, i would say a vacuous space would take more energy because a solid or liquid would act as an insulator…I googled, but couldn’t find anything…