The jewel yam, commonly available at grocery stores throughout the United States, is not a yam at all -- it is a variety of sweet potato. While this root vegetable is available all year round, the best harvest for jewel yams occurs from September through March. This vegetable has an orange flesh with a darker orange skin. The nutritional value of jewel yams makes them a go-to vegetable for good health.
One medium jewel yam -- approximately a 1/2-lb. in weight -- contains 130 calories, according to MyFitnessPal. Many people treat sweet potatoes like regular potatoes, roasting them and adding butter and sour cream for flavor. Doing so adds 102 calories from 1 tbsp. of butter and 30 calories per tbsp. of sour cream.
The jewel yam provides you with 4 g of fiber per serving, although be sure to include the skin of the sweet potato when you consume it -- a good deal of the fiber resides there. Your meal plan should include 25 to 38 g of fiber per day to maintain the health of your digestive system. The fiber in your diet also serves to help lower the amount of cholesterol in your blood, control the levels of your blood sugar and may help prevent colorectal cancer.
While the sugar content in vegetables usually isn't a problem for most people, if you have sensitivities to sugar it can present a problem. Jewel yams contain a high level of sugar -- 7 g. Despite this, the jewel yam is a low glycemic index vegetable, recommended for those with diabetes. The American Diabetes Association refers to the jewel yam as a "superfood," suggesting diabetics replace regular potatoes with these sweet potatoes.
The jewel yam contains zero g of fat, making it a good choice if you follow a low-fat diet. The majority of the calories in this sweet potato come from carbohydrates, a macronutrient your body primarily uses for energy. A medium-sized jewel yam contains 33 g of carbohydrates. The Institute of Medicine recommends consuming 130 g of carbohydrates each day, as well as 46 to 56 g of protein. One jewel yam provides you with 2 g of protein, so be sure to adjust your meal plan accordingly to meet your daily nutritional goals.
Vitamins and Minerals
Including jewel yams in your diet gives you a big boost of vitamin A -- one medium yam provides you with 440 percent of the daily recommended intake of this vitamin. This makes the jewel yam an excellent choice to maintain the health of your eyes. Vitamin A influences both regular vision and night vision. It also plays a role in maintaining healthy skin and teeth. Jewel yams also serve as a rich source of vitamin C. One serving of yams contains 30 percent of the vitamin C you need each day, as well as 2 percent of the iron and calcium your body requires daily.