A lot of people believe that eating fiber with a meal helps block the absorption of fat. That’s true but only on a very small scale. The real fat-fighting benefit of fiber is the full factor—eating more fiber helps you feel full faster, so you eat less. It also helps you feel full longer, so you don’t get hungry so soon after a meal. It actually slows the transit time of food through the digestive tract and keeps things moving through the bowel. If you tend to overeat, it’s a good idea to have a fairly large salad before your main course, as the fiber in lettuce will curb your appetite. Be sure to skip the cheese and croutons.