[3pt14159]

In the long run you'll want to eat them with butter, not just boiling them. Otherwise there are some nutrients that you'll miss. Even so, potatoes cover a huge swath of the nutritional profile that a person needs. It's one of the reasons that potato famines are so devastating. Switching to grain flour alone doesn't make up for the difference.

[mahathu]

Serious question because I am also interested in this, what about micronutrients in fruits/vegetables, fish etc.?

[3pt14159]

I don't know why I was downvoted, but the answers you are looking for are available on a now offline website called WHFoods (World's Healthiest Foods) which you should be able to find on Archive.org or similar.