The giant panda is around 1m tall at the shoulders and weighs about 100 kg. Males typically weigh about 10% to 20% more than females. Their large size allows it to lose heat more slowly than small animals, owing to a decreased body surface area: body volume ratio; if its metabolic rate is lower, meaning that it needs to consume fewer calories to stay alive at any given temperature. Thus, giant panda would not find it difficult to feed on such a nutrient-poor food, bamboo. Moreover, per kilogram of body weight, larger animals can travel farther for the same amount of energy. The retention time of food in the gut is also increased, and excess energy is more easily stored in the form of fat.