Which statement is true about dietary fiber?

Dietary fiber is primarily composed of plant materials that the human digestive system cannot break down. This indigestible component is crucial for human health, as it aids in maintaining bowel regularity, promoting a healthy gut microbiome, and helping with the regulation of blood sugar levels.

Fiber is categorized into two types: soluble and insoluble. Soluble fiber dissolves in water and can help lower blood cholesterol and glucose levels, while insoluble fiber does not dissolve but helps with the movement of food through the digestive tract. Both types are essential for a balanced diet and offer various health benefits, such as reducing the risk of chronic diseases.

The other statements do not accurately reflect the nature of dietary fiber. For instance, fiber is not considered a lipid, nor is it easily digestible by humans, and it is not composed of digestible starches. Instead, it represents a complex carbohydrate that remains intact and contributes to overall health by fostering proper digestive function.