Do Yams Have Carbohydrates?

The holidays often include either a yam or sweet potato side dish, but either is a delicious and nutritious addition to any meal any time of year. Yams are a type of dry, starchy root vegetable, or "tuber," similar to the potato.

According to the USDA Nutrient Database, one serving of a regular yam (about one cup of cubed yam) contains:

• 177 calories
• 0.5 grams fat
• 2.3 grams protein
• 42 grams carbohydrates
  • 6.2 grams dietary fiber
  • 1 gram sugar

A type of Hawaiian yam known as mountain yam is lower in calories, carbohydrates and fiber than standard yams. According to the USDA, a one-cup serving of mountain yam yields:

• 91 calories
• 0.5 grams fat
• 2 grams protein
• 22 grams carbohydrate
  • 3.4 grams fiber
  • 0.5 grams sugar

Mountain yams have about half the magnesium and phosphorous content of regular yams and less than half the potassium content.

Other root vegetables look low in carbohydrate content compared to yams. One cup of diced Russet potatoes contains just 27 grams carbohydrate, and one cup of white potatoes contains 23.5 grams, about the same amount of carbohydrates as can be found in a serving of red potatoes.

Sweet potatoes — which many people in the United States consider interchangeable with yams, though they're different vegetables — are also lower in carbohydrates, with about 27 grams of carbohydrates per serving.

Because of the high carbohydrate content in yams, people on low- or zero-carb diets may want to avoid this vegetable. Sweet potatoes, Russet potatoes, white potatoes and red potatoes are all less carbohydrate-heavy root vegetable choices.

For the carb-conscious who want to eat yams, Hawaiian ''mountain yams'' are an alternative. One serving of mountain yams contains about 20 grams carbohydrate fewer than a serving of regular yams.