Can you sustain yourself eating only vegetables? Modern vegan diets work because we have heavily processed oils and grains, and a variety of supplements. I don't think a human could live long just munching vegetables that aren't cooked with oil.
You do not need heavily processed oils and grains nor do you need a variety of supplements. Beans and Rice contain all of the necessary proteins a human body needs for example.
B12 deficiency is an issue even for people that eat meat due to the cleaner practices and feeding where animals no longer graze but instead get their food delivered in a way that doesn't allow the animals to ingest the B12 from the dirt.
You can absolutely survive eating food that is not cooked with oil.
You could maybe make it if you ate a couple pounds of beans a day with dirt on them. I really think your digestive tract would struggle though.
We consume way more calories than we need. Should be easy with corn (part of the three sisters).
The dictionary definition of vegetable (according to dictionary.com) is:
> any plant whose fruit, seeds, roots, tubers, bulbs, stems, leaves, or flower parts are used as food
Which would include grains, however you may be excluding those depending on if "heavily processed" modifies only the oil, or the grains as well.
Of course culinarily in western traditions, grains and a lot of tubers are excluded from that, as are some fruits (others, culinarily speaking, are considered vegetables like squashes, tomatoes, and so on).
Also, in your question, would olive oil count? Its literally the result of squishing olives.... does that count as heavily processed?
Do you count potatoes? They are pretty calorie dense. Beans? Plenty of calories and lots of protein.
What about seed foods - nuts and such? They are also calorie dense and have a lot of fats too.
Point being - it's really unclear what limitations you're placing on it... peanuts, beans, (sweet) potatoes, squashes and fruits are commonly grown in home gardens, widely considered vegetables, and calorie dense enough to sustain a person fairly easily without non-stop eating.
Honestly feels great and my blood test comes back okay each time.
The only issue is when I’m away from home my options is basically Chipotle.
So, to the ancestor's point: Not just vegetables, but higher caloric-density grains.
I think the "heavily processed oils and grains, and a variety of supplements" part was also important to their point, and that's what I was disputing and qualifying.
And their assertion about "modern" vegan diets and my reference to "pre-modern" Okinawan diets is not really a contradiction either. You can easily eat the "pre-modern" Okinawan diet in Okinawa today (and in other places with grocery stores). I'm using pre-modern very loosely to indicate it is not the most common contemporary diet. Many dietary patterns across the world have Westernized/"modernized" (and as a result, many, though by no means all, have become less healthy).
The comment talks about eating "only vegetables", but it's being misinterpreted as "can you survive on a vegan diet" and even "do vegetarians exist"
The question was "can you survive eating only vegetables?" No beans, chickpeas, peanuts, no nuts, no grains, no fruit.
(according to oxford):
a plant or part of a plant used as food
(according to webster):
a usually herbaceous plant (such as the cabbage, bean, or potato) grown for an edible part that is usually eaten as part of a meal
(according to dictionary.com)
any plant whose fruit, seeds, roots, tubers, bulbs, stems, leaves, or flower parts are used as food
Which should include beans, chickpeas, peanuts, nuts, fruit, grains, etc.
If the question was about something else, maybe they should have used the words that mean what they want to ask instead?
So tomatoes are out?