Other causes of stomach rumbles: 1  Incomplete digestion of food can lead to excess gas in the intestine. 2  Louder rumbles may occur when one is hungry. 3  Stomach rumbles can form further along the gastrointestinal system when air is swallowed while talking, eating, and drinking.
One cup of raw yams contains about 158 calories, whereas 1 cup of raw sweet potatoes contains about 114 calories. Therefore, yams contain about 44 more calories than sweet potatoes for an equal portion.
While sweet potatoes do contain sugar, they also contain beneficial elements that are complimentary to your health and body. The sugar content in sweet potatoes is 4.2 grams for every 3.5 ounces of sweet potatoes that you ingest. While not terribly high or alarming, this confirms the presence of sugar just the same in sweet potatoes. As with all things, excess is bad, and this applies also to your sugar intake.