Some reasons given why human body is designed to be vegetarian:

Meat-eaters: have claws
Herbivores: no claws
Humans: no claws


Meat-eaters: have no skin pores and perspire through the tongue
Herbivores: perspire through skin pores
Humans: perspire through skin pores



Meat-eaters: have sharp front teeth for tearing, with no flat molar teeth for grinding
Herbivores: no sharp front teeth, but flat rear molars for grinding
Humans: no sharp front teeth, but flat rear molars for grinding


Meat-eaters: have intestinal tract that is only 3 times their body length so that rapidly decaying meat can pass through quickly
Herbivores: have intestinal tract 10-12 times their body length.
Humans: have intestinal tract 10-12 times their body length.


Meat-eaters: have strong hydrochloric acid in stomach to digest meat
Herbivores: have stomach acid that is 20 times weaker than that of a meat-eater
Humans: have stomach acid that is 20 times weaker than that of a meat-eater


Meat-eaters: salivary glands in mouth not needed to pre-digest grains and fruits.
Herbivores: well-developed salivary glands which are necessary to pre-digest grains and fruits
Humans: well-developed salivary glands, which are necessary to pre-digest, grains and fruits


Meat-eaters: have acid saliva with no enzyme ptyalin to pre-digest grains
Herbivores: have alkaline saliva with ptyalin to pre-digest grains
Humans: have alkaline saliva with ptyalin to pre-digest grains