We can say with Cuvier and Letourneau that "man is a mammal, fitófago, frugívoro". Such a definition is correct not only from the point of view of their dental conditions, most also taking into account the physiological capacity of their digestive processes.
The digestive juices of the human stomach is unfit to digest meat, as they are extremely weak. If brown rice, beans, wheat, masses and various grain products require an average of four hours to metabolism, how long you will require meat?
The agency considered healthy, meat remains no less than 8 hours to be assimilated. In individuals suffering from gastric fever, slow digestion, constipation and intestinal disorders, they remain between 12 and 24 hours, producing a congestion throughout the digestive tract.
The digestive juices of carnivorous animals are much stronger than those of herbivores and frugivores, and insert the man in context. In the case of dog, cat or lion, the meat can be assimilated in a relatively short period: 2 or 3 hours. In a scientific fact it recognized that animals that eat meat have much shorter intestines, than those who eat plants.
The animals that feed on herbs and man, have long intestines too.
Cat gut, for example, is 3 times the length of its body. The ram (herbivore) twenty times, and the man and apes, have bowel 7-8 times longer than their bodies.
The meat itself is indigestible, and because of this, the saliva does not alter its composition to be received as food, although it is well chewed.
