All varieties of sweet potatoes are a healthy source of dietary fiber, antioxidants, are low in calories (1 whole cooked potato = around 103 calories), with no fat or cholesterol. One key difference among varieties is that purple-fleshed potatoes have the highest amount of anthocyanin antioxidants. While the jury is still out on the positive impacts of anthocyanins, research is indicating numerous positive benefits, including protecting against everything from obesity and diabetes, to cardiovascular disease and cancer. (Source: www.livestrong.com)