What things do our bodies use energy for when we are sleeping?

Our bodies use energy when we are sleeping for . . . * Keeping our lungs going so we can still breathe. This of course, happens involunterly. * Keeping our brains working. They send out all of the vital messages and make sure our organs keep operating. They will register pain and present images in our subconsious i.e. dreams. * Maintaining body temperature. * The digestion of food. * Regeneration. While we don't require energy for other things, the body will use it to heal injuries and refresh the body. Your brain also uses energy to store memories.