What is the primary function of dietary fiber?

The primary function of dietary fiber is to promote digestive health and regularity. Dietary fiber encompasses components found in plant foods that are not digested by enzymes in the human gastrointestinal tract. This characteristic allows fiber to assist in maintaining bowel health by adding bulk to the stool and encouraging regular bowel movements, which can help prevent constipation. Moreover, fiber plays a crucial role in overall gut health, including feeding beneficial gut bacteria and supporting a healthy microbiome.

Fiber can be categorized into two types: soluble and insoluble. Soluble fiber can help with cholesterol levels and blood sugar control, while insoluble fiber is essential for adding bulk to the stool and promoting movement through the digestive system. Consuming an adequate amount of dietary fiber is linked to reduced risks of gastrointestinal diseases and can be instrumental in maintaining a healthy weight.

The other options relate to functions that fiber does not primarily fulfill. For instance, while muscle mass increases typically result from protein intake and resistance training, fiber itself does not provide essential amino acids. Similarly, fiber does not have a direct role in speeding up metabolism or increasing muscle mass. While a well-rounded diet and good digestive health can support overall metabolic health, dietary fiber primarily functions to improve digestive health and regularity.