The TRUTH about Potatoes, Glycemic Index, and "White Foods" - Friend or Foe for Fat Loss?
White potatoes are actually a healthy carbohydrate as long as you eat them in the right form... with the entire skin, and please don't ruin them by deep frying them into french fries either! French fries are one of the most evil things ever invented for your health, but only because we ruin them by soaking them in a scorching bath of trans fats in the deep fryer from the hydrogenated oils that are typically used.
Keep in mind that potatoes contain so many vitamins and minerals that the list is way too long to even try. Also, as long as you eat the skins, you get a decent shot of fiber too.
and here is an article worth reading more than once:
Why White Bread is Bad for You