Well they have been eating bamboo for 2 million years according to the article. While they are not completely adapted, they have probably made at least some ada

Well they have been eating bamboo for 2 million years according to the article. While they are not completely adapted, they have probably made at least some adaptions. So a meat diet may not be optimal. This is similar to humans. Our diet has changed a great deal in recent evolutionary history. E.g. eating cooked meat, or large amounts of processed grains. But that's not quite as severe as switching to eating bamboo.