What role does dietary fiber play in a healthy diet?

Dietary fiber plays a crucial role in maintaining bowel health. It is a type of carbohydrate that the body cannot digest, which is why it helps to regulate the body's use of sugars, helping to keep hunger and blood sugar in check. Fiber adds bulk to the stool, making it easier to pass and reducing the likelihood of constipation. This bulkiness promotes regular bowel movements and can aid in the prevention of digestive issues, such as hemorrhoids and diverticular disease. Furthermore, a high-fiber diet is often associated with a lower risk of developing significant conditions like colorectal cancer, as it supports a healthy gut microbiome and promotes digestive health.

The other options don't accurately represent the role of dietary fiber: protein absorption, essential fats, and a primary source of calories are not functions of fiber, but rather pertain to other nutrients like proteins and fats.