Actually this has already been done, it was how we discovered that potatoes are not toxic. For centuries everyone believed that were super toxic and throw them

Actually this has already been done, it was how we discovered that potatoes are not toxic. For centuries everyone believed that were super toxic and throw them in the woods in hoping of killing wolfs and boars. During one the many war between french and germans, french has captured a POW and as torture they fed him only with potatoes for more than a year, thinking of slowly killing him. He went out of prison in better shape than when he entered