Is yam a fiber food?

Not particularly: See this site for a list of high fiber foods. http://www.mayoclinic.com/health/high-fiber-foods/nu00582.

> sweet potato: Yams are unusual in the U.S.: most are huge, pale colored and African in origin. They have about 4 grams of fiber in a 100gram serving, which is high. Sweet potatoes are often mislabeled as yams, because that is the term that people know. Sweet potatoes can look like potatoes, are every color of the rainbow, and have fewer calories, less fiber and about 100x the beta carotene as do yams.