In recent years, fat has been replaced by sugar as public health enemy No. 1, with cases of obesity and diabetes continuing to spiral. Yet the human palate craves sweetness. So it's no wonder people have been on the hunt for alternatives to the common table sugar that is associated with a wide variety of health issues. Refined table sugar, or sucrose, has basically no vitamins, minerals, or fiber, leading to its reputation for adding "empty calories."
Archaeological evidence suggests they were cultivated in South America more than 4,500 years ago, says Michelle Johnson, a seed historian, journalist and self-described sweet potato superfan. Flavorful, productive, resilient and adaptable to a wide range of climates, the entire Ipomoea batatas plant is edible, and has thousands of cultivars; about 20 are sold commercially in the US, says Johnson. Surprisingly, they are kin to morning glories but unrelated to either white potatoes or yams.