As the bamboo has a low nutritional value, the Giant Panda has to spend a lot of time eating, and that is why their sleeping time cannot be too long. They sleep for 2-3 hours at a time, and then spend 3-4 hours eating. This sleeping mode can sustain a stable energy intake, and explains why they sleep right after they are full and eat right after they are awake, just like they do in a zoo.