Herbivorous and carnivorous possess teeth specialized to their diet. Man has a multifunctional set of teeth with characteristics between herbivorous and carnivorous so can eat both meat and vegetables. Gastric juice in our stomach is less acid than in a stomach of a carnivorous but more acid than in a stomach of an herbivorous. The length of our intestine is shorter than in a herbivorous but longer than in a carnivorous. Herbivorous can digest cellulose, man cannot. No vegetable contains all the essential amino acids we need. Vitamin B12 is found only in animal products.