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If you could choose any food, and that food would be the only one you'd eat for the rest of your life, what would it be? After ruling out some of the more blatantly appealing cases:  too much ice cream makes me nauseous, as much as I like it I think I'd get sick of steak, noodles aren't as versatile as I'd like, especially without other ingredients, I decided that there could only be one correct answer: Potatoes.

Which is why I'm thrilled to discover that that's actually a real option!

According to Wikipedia, the quoted source for this image:

Humans can actually survive healthily on a diet of potatoes supplemented only with milk or butter, which contain the two vitamins not provided by potatoes (vitamins A and D).[37][38] The potato contains vitamins and minerals, as well as an assortment of phytochemicals, such as carotenoids and natural phenols.

I now have a well-researched answer to this popular hypothetical:  Potatoes are not just a great answer, they are the correct answer.