what is consumed by humans that provides energy but is not an essential nutrient
Nutrient Non-essential nutrients are substances within foods that can have a significant impact on health; these substances can be beneficial or toxic.[medical citation needed] For example, dietary fiber is not absorbed in the human digestive tract, but is important in maintaining the bulk of a bowel movement to avoid constipation.[medical citation needed] A subset of dietary fiber, soluble fiber, can be metabolized by bacteria residing in the large intestine.[19][20][21] Soluble fiber is marketed as serving a prebiotic function – promoting "healthy" intestinal bacteria.[citation needed] Bacterial metabolism of soluble fiber also produces short-chain fatty acids like butyric acid, which may be absorbed into intestinal cells as a source of calories.[19][20][21]