I think the actor doing Jobs had some pancreatic problems related to eating like Jobs.

Don't quote me on that, please double check.

Likely. It probaby wasn't the only thing though. The high amounts of sugar, weird fasting habits, drug use, extreme stress he put himself in, and his arrogance in ignoring sound medical advice might have all helped do him in from what I gleaned from his biography. His pancreas could only take so much apparently.

There are a lot of plants that you can eat a little part of, which then grows back, like the leaves on chard or lettuce plants. In our garden the chard plants produced for months.

In commercial farming, it's just cheaper to cut the entire plant off and clear the land for the next crop.

See also: https://en.wikipedia.org/wiki/Jain_vegetarianism