Article By: Maria Tucker, MPH, RDN, LDN, CDCES
Maria Tucker is a Registered Dietitian and Certified Diabetes Educator with over 20 years of experience assisting patients with diabetes, obesity, and nutrition-related conditions. Maria is also the Founder of MyBiyaya.com, a site dedicated to healthy recipes and kitchen shortcuts.
1) What is dietary fiber? Defining fiber can be tricky. The US Institutes of Medicine Food and Nutrition Board defines fiber as the non-digestible carbohydrates and lignin that are intrinsic and intact in plants. The definition of dietary fiber has been further subdivided...
Based on its natural availability
- Dietary fiber - components of plants’ cell wall materials such as fruits, vegetables, and nuts
- Added fiber - indigestible carbohydrates extracted from either plant or animal sources that have beneficial health effects in humans.
Based on its chemical properties
- Soluble fiber - a type of fiber coming from the inner flesh of plant foods that dissolves in water and forms a gel-like material. Soluble fiber is fermented in the colon by gut bacteria. This type of fiber, including gums, mucilage, and pectin, is what is said to help with lowering blood sugar and cholesterol. Food sources of soluble fiber include barley, beans, peas, broccoli, carrots, oats, and root vegetables.
- Insoluble fiber - a type of fiber coming from the peel or skin of plants. Insoluble fiber does not dissolve in water and is not fermented by gut bacteria in the colon. This fiber, which includes cellulose, hemicellulose, and lignin, helps by giving bulk to stool and preventing constipation. Examples of foods containing insoluble fiber include corn, potatoes, veggies (such as zucchini, green beans and cauliflower), as well as bananas and avocado, whole grains, nuts, and seeds.
2) How does fiber help with weight loss? In 2019, an article published in the Journal of Nutrition from the American Society of Nutrition, analyzed a study to “assess the role of dietary fiber as a predictor of weight loss in participants who consumed calorie-restricted diets for 6 months”. Data from the POUNDS (Preventing Overweight Using Novel Dietary Strategies) Lost Study was used for this analysis, which concluded that fiber intake, independent of calorie and macronutrient intake, promotes weight loss and dietary adherence in persons with obesity.
When looking at the effect of fiber on weight loss, it is important to note that viscous soluble fiber is the type of fiber that is most associated with aiding weight loss. There are a few types of viscous soluble fiber including beta-glucans, glucomannan, guar gum, pectin, and psyllium. Viscous fiber does not dissolve but thickens in water, forming a gel-like substance in your stomach that slows down digestion and passage of food from the stomach into the small intestines. This slowing down of digestion makes you feel full longer and decreases appetite. It keeps you from getting hungry sooner, preventing overeating and mindlessly grazing on food.
3) Which foods contain viscous soluble fiber? Foods with viscous soluble fiber include apples, bananas, barley, beans, bran, Brussels sprouts, carrots, oats, sweet potatoes, and turnips to name a few. Eating these foods may help suppress your appetite and help you stay on track with your weight loss goals.
4) How much fiber do I need to have in my diet every day? The Academy of Nutrition (AND) recommends that adult women consume 25 grams of total fiber per day and adult men consume 38 grams of total fiber per day. However, in 2015, AND noted that most Americans consumed only an average of 17 grams fiber daily and only 5% of the US population consumed adequate amounts of fiber.
With the many benefits of a high fiber diet (including promoting weight loss) it is a no-brainer that fiber should be an important part of your healthy diet. So, what are you waiting for? Go forth and fiber up!
BariMelts provides general recommendations, not to be construed as medical advice. Please consult your doctor.