I am far from being vegan or vegetarian but have a rather strange dietary lifestyle....most weekdays I only have juice and coffee for breakfast, some fruit in mid-mornings (bananas, berries, mango, 'chew and spit' fruits like pineapple or melon...) then for lunch it is whole grain breads with seeds, dried fruits or nuts in them with chunks of cheese. Sometimes I have another yogurt or split the bread and cheese into 2 small meals at noon and 4pm. For dinner, it is often meatless like tonight: pasta with a tomato/olive/eggplant sauce.
I do not do this intentionally or for moral reasons (I am not that disciplined) but out of simplicity and necessity...no time to eat during the day and always on the run (or on the limp). I don't drink sodas or sugary drinks or even juice other than in the mornings...Water, tea or coffee (my drug).
For me, giving up meat would be easy but because of my pouch I cannot replace it with beans of any sort (I can eat 1 bean but not 2!) or cooked leafy veggies like spinach or kale...they are not pouch-friendly for me. (but may work just fine for you).
Nuts can be a big part of your diet and offer you quality proteins along with dates and other dried fruits. Beware of raisins and apricots...they can liquify some people's output.
For years I practically lived off of rice and sauce (homemade, rich sauces), whole grains and dark breads with raisins, cans of tuna and sardines with salad.
So it is possible but you must start any change slowly, give your body time to adapt, stop if your body is telling you to and move forward with prudence.
Good luck and keep us posted
Sharon