Potatoes' nutritional pros and cons

Most of us have heard about the cons re potatoes and obesity.
Here's an article that shows a study postulating that potatoes are part of what keep the french thin - something about polyphenol richness...

Oh, wait, the study was with canadian (I take it) mice.
Also, it's not clear if it was the research team that postulated about the french and potato polyphenols, or the article author. . but I take it that the research team did.

http://www.grubstreet.com/2014/12/potatoes-obesity.html

a clip from the article:

A team of McGill University researchers published a paper this week that includes what is likely the most shocking thing about potatoes any of us will hear all week: In an experiment, potato consumption was shown to decrease body weight gain.

It should be mentioned that this all went down in a laboratory, and it was tiny mice bingeing on the tubers. They were Irish potatoes, too, if that makes any difference. Most important, the potatoes were ingested in the form of an extract, a painstakingly prepared polyphenol-rich extract made from lots and lots of potatoes — about 30 per daily dose.

But still, the specifics of how a bunch of mice weighing an average of 25 grams were fed an "obesity-inducing diet" and some stayed thin while the others got fat are interesting. The ones who didn't get the magic potato serum gained "about 16" grams, while the ones who did gained seven. Researchers were baffled and repeated the experiment with "potatoes grown in another season."
end/clip

The french show up toward the end of the article. (worth a look, I think)