Hippos actually eat quite modest amounts compared to other large herbivores. Although consumption of grass and fallen fruits varies, the average amount eaten is somewhere between 35-45 kg per night, about a third of the diet of similar sized herbivores. Studies have shown that hippos can survive by eating only around 1.5 percent of their own body weight. This compares to around 2.5 percent for large cattle. Hippos are normally relatively inactive during the day and conserve energy by resting in the water, though they have been known to travel up to 10 km at night in search of food, when grazing is poor. Hippos also have quite a slow digestive process, which helps in obtaining the necessary nutrients from their small meals.