Body Parts

How Fiber Works

You’ve probably heard fiber is important, but do you know how it works to help keep you full?

Learn More!

Rollover parts of the digestive system to find out more on how fiber works in your body.

Mouth: The gatekeeper.

Some fiber-rich foods may increase the time and effort spent chewing – and, both of these may be the first steps to improved fullness. One of the reasons why increased chewing may influence satiety is because chewing increases saliva production and potentially leads to a larger volume of food and fluids entering the stomach.

Stomach: The holding tank.

Certain types of fiber may empty from the stomach into the small intestine more slowly than others. And, slow steady emptying may contribute to greater feelings of satiety.

Small Intestine: The traffic cop.

Certain types of fiber may empty from the stomach into the small intestine more slowly than others. And slow, steady digestion may help contribute to greater satiety because food & fiber can take longer to move from the small intestine into the large intestine. It’s possible that prolonged transit time means the nutrients (carbohydrate, proteins, and fats) associated with the fibers are digested and absorbed more slowly.

Large Intestine: The final stretch.

When fiber reaches the large intestine, good bacteria are ready and waiting to break it down. As the fiber is broken down, it is hypothesized that this process may contribute to improved satiety.

Brain: The control center.

As food moves through the digestive tract, many satiety-related signals are sent to the brain. Research indicates that some fiber-rich foods may play a special role in triggering the release of these satiety-related signals. This process is important since the brain is a key appetite regulating center of the body.


  1. Slavin JL. Nutrients. 2013;5:1417-1435.
  2. Wanders AJ et al. Obes Rev. 2011;12(9):724-39.
  3. Kristensen M et al. Appetite. 2011;56(1):65-70.
  4. Howarth NC et al. Nutr Rev. 2001;59(5):129-39.

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