How much do snow monkeys eat?

There has been little research done on how much the Snow monkey eats, but it is known to eat more during certain seasons.
Depending on the region in Japan in which it lives, the Snow monkey (also known as the Japanese macaque) eats young leaves, shoots, fungi, seeds and flowers during the spring and summer seasons. In order to build up stores of fat for winter, it eats more during autumn, feeding on fruit and nuts. In winter it eats buds and bark, but sometimes it will also feed on birds eggs and even crabs.