This is a great question. The USDA requires us to follow the USDA guidelines on potato nutrition, which group brown, red, yellow, and niche varieties of potatoes together, with the exception of sweet potatoes. The composition of the average potato is still about 80% water and 20% starch and nutrients. Whenever I have seen testing results on one variety of potato having more iron than another, the amount is very negligible.

This link is helpful for calculating calorie and nutrition information when preparing different types of potatoes: http://nutritiondata.self.com/

You may also find useful nutrition information on the beneficial aspects of eating potatoes at this link to Idaho Potato Nutrition Information.

Finally, this link shows some of the sources of food analysis: http://www.ag.ndsu.edu/foodent/test.htm

You can’t go wrong eating a heart-healthy Idaho potato!