When fiber is in your stomach, it absorbs water and swells, slowing the digestive process and helping your stomach feel full. That way, you won’t want to eat more than you need to, and you won’t be hungry soon after you snack. Fiber then passes through your digestive tract, acting like a broom to sweep out the bad stuff, keeping you feeling good. Fiber also keeps your blood sugar levels steady by providing a slow release of energy, rather than a rush of sugar that you’ll burn through quickly.