Fullness in tummy. Fiber makes us feel full sooner and stays in our stomach longer than other substances we eat, slowing down our rate of digestion and keeping us feeling full longer. Due to its greater fiber content, a single serving of whole grain bread can be more filling than two servings of white bread. Fiber also moves fat through our digestive system faster so that less of it is absorbed.
If fewer calories. Eating foods or drinking drinks that contain fiber can help with weight loss only if they don't increase the total amount of calories eaten per day. For example, mixing water with powdered fiber to make a drink will cause a person to feel fuller and have less appetite (can be helpful). However, mixing fiber with orange juice will give a person lots of sugar calories along with fiber (won't help!).