 Because in addition to your protein, like eggs and lean meats and fish, we need fruits and vegetables to the tune of 10 servings per day. You heard that right. 10 servings per day. The only way I know how to get as many as that and in the best and easiest way possible and not spending and breaking the bank is by buying Balance of Nature. The fruits and vegetables are all in there. A variety of 31 of them.