Us humans have an omnivore mouth and gut. If one wishes to eat something different, well more power to ya, but you have to make sure you're getting the proper nutrition.
I've been a vegan vegetarian (mostly-for a while i vacillated between lacto-veg and vegan) for a couple of years. i lost a bunch of weight, still have a bunch to go, and i get my blood drawn regularly to monitor my nutrition levels.
I probably eat a 75% raw diet. fresh fruit and salads are a part of my daily diet. and by salad i don't mean a few pieces of leaf lettuce smothered in dressing. i mean lots of greens, broccoli, cauliflower, peppers, onion, carrot etc. i make my own dressing.
as for cooked foods, i have whole wheat pasta, brown rice, beans etc. i roast root veggies too. '
I'm also into juicing. dark greens, carrots, a little fruit. daily.
a Vita Mix or similar blender plus a good juicer ( i have an Omega 8004) is a must, IMO.