I can't see myself living as a vegan. I am a die hard carnivore and without eat, i find it very hard to live in this world
I was actually a vegetarian for four years, but now I eat a bit of meat. I guess we're both omnivores then as we eat both animal and non-animal food.
How could you go without me for all of those years. Just eating plant based food won't give you necessary and essential nutritions for a healthy body
I don't believe that's true, I did out of environmental concerns, but some people also do it for cultural and political reasons.
I can understand your stance on environmental issues, but still life is all about survival and it does everything to be as fit as possible
I suppose that's true, but humans are not obligate carnivores, as in we are not solely dependent on meat products for nutrients. Fitness also refers to reproductive ability, I don't think a vegetarian diet influences that. 
Well, i think to certain extent it deprives you of some essential sources of nutrition and that will definitely have its negative impact in the long-run
Which nutrients do you think are lacking? The only one I can think of is B12, and that's necessary for vegans not vegetarians.