Question

Based on structure of our digestive system ,what kind of shall we take -vegetarian and non-vegetarian? why?

Answer 1

Our sharp canines are designed for tearing flesh, not fruits.  Our digestive systems produce enzymes designed for breaking down animal proteins, and are incapable of digesting cellulose (which almost all herbivores can). 

In fact, getting the proper mix of amino acids just from plants is a difficult task (not impossible, certainly, but vegans need a well-planned diet to avoid health problems, which our ancestors didn't have the benefit of).

Antropologists have concluded that humans have been eating meat for over two million years, more than enough time for us to adapt to such a diet biologically.  Our bodies are thus, designed such a way that  eating only meat would kill us, but getting at least some meat in our diets appears to be quite beneficial.