Purple and blue foods are an excellent source of nutrients. They foods derive their shade from the antioxidant Anthocyanin. It is a very energy defence towards cell damage and attacks on your immune system. Foods in this group include blueberries, purple grapes, boysenberries, eggplant, red cabbage, beetroot.
Purple yams are calorie-dense; a 125-g purple yam provides 177 calories. This amount comprises nearly 9 percent of the total daily suggested intake of 2,000 calories, and is 65 calories more than a 125-g sweet potato. You could burn off the 177 calories in a purple yam by doing about 30 minutes of low-impact aerobics.
Purple yams are rich in carbohydrates; each 125-g yam provides 42 g of carbohydrates. None of these carbohydrates come from sugar, while 6 g come from dietary fiber, a nutrient that promotes feelings of fullness. Purple yams are better carbohydrate sources than sweet potatoes; a 125-g sweet potato contains just 26 g of carbohydrates, with 8 g of sugar and 4 g of fiber.
Purple yams, like other types of potatoes and starchy foods, are low in protein. A 125-g purple yam contains just 2 g of protein. Protein is an essential nutrient that aids in building the cells and tissues of your body; MedlinePlus suggests consuming 50 to 65 g of protein each day to ensure proper health.
Purple yams are naturally low in fat. Each 125-g serving of purple yam contains just .25 g of fat. Dietary fat is high in calories, but it does provide nutritional benefits, including promoting the absorption of some nutrients and assisting in healthy growth and development.