Was the human race vegetarian before before the great flood?

The human species has never been vegetarian entirely, subsisting on both meat and vegetable matter.

According to The Bible, before the great flood humans and all the other animals had a vegan diet -

Genesis 1:29-31 (NIV)

29 Then God said, "I give you every seed bearing plant on the face of the whole earth and every tree that has fruit with seed in it. They will be yours for food. 30

And to all the beasts of the earth and all the birds in the sky and all the creatures that move along the ground---everything that has the breath of life in it-I give every green plant for food." And it was so.