Are sweet potatoes healthy?

"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."

"A medium orange sweet potato (about 140g, or one serving, cooked) contains around 130 calories, 30g of carbohydrates and 2g of protein. Most of the carbs come from complex starches, or slow-digesting chains of glucose molecules; less than half derive from their approximately 10g of simple sugar. How you prepare a sweet potato can affect sugar content and glycemic index, or the speed at which a food causes blood sugar to rise."

Sweet potatoes were domesticated in South America over 4,500 years ago and belong to the Ipomoea batatas species, related to morning glories rather than white potatoes or yams. The whole plant is edible and thousands of cultivars exist, with about 20 sold commercially in the US. A cooked medium orange sweet potato (~140g) provides ~130 calories, 30g carbohydrates, 2g protein, and 4–6g fiber. Most carbohydrates are complex starches; preparation alters sugar content and glycemic index—steaming or boiling preserves resistant starch and lowers GI, while high-heat roasting increases maltose and raises GI. Fiber aids blood-sugar stability, cholesterol reduction, and satiety.

Read at www.theguardian.com