Overloading your refrigerator might harm it by making air circulation more difficult. This can interfere with its capacity to regulate internal temperature and keep your products cold. Its inability to regulate its temperature puts additional strain on the compressor and condenser coils, which can lead to overheating.
Similarly, underfilling your refrigerator might result in harm. Keeping cold products in your refrigerator helps to maintain a low interior temperature. With fewer goods in there, there is less food to assist keeping your fridge cold, causing your refrigerator to work more to maintain the proper temperature.