WTN- Could be due to thier lazy lifestyle, sloth mailnly consumes plant leaves. However, but leaves do not provide very much energy or nutrition, sloths eat much amount of leaves due to very big stomachs.

These mammals are considered to have one of the lowest mass-specific metabolic rates of any mammal and, in tandem with a slow digestive rate. 

Sloths are omnivores, meaning that they eat both plants and meat. But like many other things they do, sloths eat and digest slowly. In fact, a sloth can take up to one month to digest a single meal.