Here is a wonderful article on Plant Based Diets and how they can vastly improve your health and weight loss routine. I am personally looking into this more and more as the information leads me to believe this may be the way to go. PS: they make plant based protein powders as well for those looking to increase mass.
http://www.huffingtonpost.com/carole-bartolotto/plant-based-diet_b_3807973.html