Is there a single food that you can survive on forever?

(via Popular Science) For all of 2016, Andrew Taylor ate only potatoes. There were a few caveats: He ate both white potatoes and sweet ones, and sometimes mixed in soymilk, tomato sauce, salt and herbs. He also took B12 supplements. He took four blood tests over the year which he claims all came back normal. He even lost weight and felt more energized.