By Roberta H. Anding, MS, Baylor College of Medicine and Texas Children’s Hospital

Edited by Kate Findley and proofread by Angela Shoemaker, The Great Courses Daily

Eating a high-fiber diet is helpful for cholesterol reduction, diabetes management, and preventing digestive diseases. But did you know it can also keep your weight down while simultaneously helping you feel less hungry? Professor Anding explains.

Fiber and Weight Management

Eating a high-fiber diet helps us to reduce the risk of developing type 2 diabetes by controlling blood sugar levels. This benefit is not only due to the fiber but also to the whole grain foods that are a source of magnesium. Magnesium is lost in the processing of whole grains and is not added by fortification. Additionally, these high-fiber foods—particularly those containing primarily water-soluble fiber—help with weight management because we feel full and satisfied after consuming them.

The health media often promotes eating oatmeal for breakfast as a means to lose weight. There is some science to suggest that the water-soluble fibers found in oatmeal stay in your stomach a little longer and therefore contribute to that feeling of fullness. However, you want to make sure to use plain oatmeal as many instant oatmeals are high in added sugar.

Additionally, consuming these types of fibrous foods requires that you thoroughly chew your food. It takes more effort to get the calories to where they need to be. 

The more you chew your food and the longer it stays in your stomach, the more likely you are to feel full. It allows your body to signal when you are full, so overall food intake is lower. 

Why High-Fiber Leads to Fullness

As part of any weight-reduction strategy, having more fiber in your diet of both forms—soluble and insoluble—can promote overall fullness. Foods containing primarily insoluble fibers include celery, nuts, and many vegetables, while soluble fibers can be found in apples, bananas, and beans.

Ultimately, because you have a volume sensor in your stomach and not a calorie sensor, the longer your stomach is dilated from these high-fiber foods, it sends chemicals to your brain. In essence, it makes a meal seem larger and last longer so you’re satisfied for longer periods of times, and feelings of hunger are delayed.

High-fiber diets can oftentimes be termed as less energy dense. This means you are consuming fewer calories for the same amount of food. High-fiber foods—which again, include nuts, fruits, vegetables, legumes, and whole grains—are also nutrient dense, which leads to feelings of satisfaction and nourishment after a meal, in addition to enhancing your overall health.

Fiber and Colon Cancer

Along with weight management, fiber can alleviate or prevent constipation by helping food to move through your large intestine more easily. Fiber can also treat gastrointestinal conditions, such as irritable bowel syndrome. The jury is still out, though, regarding the effect of a high-fiber diet in the management of colorectal cancer. The results of studies vary. 

Some studies show benefits, some show no benefits, and some even show greater risk. A lot of this depends on what stage of development a person’s cancer diagnosis is. The best prevention of colorectal cancer is a healthy diet, along with regular screenings. 

“If you’re tempted to look at the latest, greatest whatever is in the newspaper regarding fiber and colorectal cancer, keep in mind a healthy diet is always going to be advantageous, but is never going to prevent you from staying away from your doctor and getting that regular screening for colon cancer,” Professor Anding said.

Overall, a high-fiber diet can be highly beneficial in weight management and disease prevention as it contains nutrient-rich foods that nourish your body. However, you should not look for shortcuts to increase your fiber intake, such as taking a fiber supplement or consuming processed foods that are fortified with fiber. Typically, these shortcuts lack the benefits of regular food sources that naturally contain fiber.

This article was edited by Kate Findley, Writer for The Great Courses Daily, and proofread by Angela Shoemaker, Proofreader and Copy Editor for The Great Courses Daily.

Professor Roberta H. Anding is a registered dietitian and Director of Sports Nutrition and a clinical dietitian at Baylor College of Medicine and Texas Children’s Hospital. She also teaches and lectures in the Baylor College of Medicine’s Department of Pediatrics, Section of Adolescent Medicine and Sports Medicine, and in the Department of Kinesiology at Rice University.