Updated: Mar 1, 2020
So, it's time to get serious. Your favorite pants are a little snug, or maybe you just want to stop the slowly increasing numbers on the scale. Fortunately, there is no need to starve yourself or begin a new fad diet. One of the best ways to tip the scales in your favor is to add fiber to your diet.
The role of fiber in weight loss
What is fiber? Fiber is the part of plant-based foods such as fruits, vegetables, grains, nuts, and beans that the body can't break down. Fiber is not found in meat, fish, poultry, milk or eggs and there is little to no fiber in processed "junk" foods. While, technically, our bodies cannot digest fiber, our gut bacteria - the beneficial, good gut bacteria - thrive on it. The short-chain fatty acids produced by the breakdown of fiber in our bodies have a wide-ranging effect on everything from boosting immune function and lowering inflammation to regulating appetite, metabolism and body fat.
For many Americans, about 95% of which do not meet the minimum guidelines for fiber intake, adding fiber to the diet can have benefits beyond regularity. Adequate fiber in the diet not only assists with digestive health and weight loss, it is associated with "reduced risk for heart disease, stroke, hypertension, certain gastrointestinal disorders, obesity, type 2 diabetes, and certain cancers."
Because fiber is considered to have zero calories, it adds bulk to food without adding extra calories. This increase in bulk in the digestive system can naturally lead to a drop in your daily caloric intake. Additionally, one study found that subjects that consumed higher-fiber diets lost more weight than those who ate less fiber, even when the caloric intake was the same.
Fiber may be one of the best tools in our weight loss arsenal. To get a better picture of the impact of fiber, let's compare apples with apple juice.
What about fruit juice?
Fruit juice is basically just fruit minus the fiber. Even orange juice with "extra pulp" does not significantly add additional fiber to the diet. Fruit juice tastes delicious, but eating whole fruit, rather than drinking fruit juice, should be the choice of anyone trying to lose or maintain their weight, or for those trying to control their blood sugar levels.
Fruit juice can deliver a quick and powerful sugar and calorie punch to your diet. For example, you could choose to drink 16 ounces of apple juice, which could easily be consumed in a few minutes. Consuming the same amount of sugar and calories by eating the apples themselves, would take much more time and metabolic energy, since the sugar is packaged in fiber. In fact, you would need to eat over four cups of apple slices to get the same number of calories in a 16-ounce glass of apple juice. Chewing and swallowing four cups of apples amount takes time and energy. Foods rich in fiber take more time to eat, giving your brain time to get the signal that your stomach is full.
Unfortunately, fiber supplements, like Metamucil, can promote regularity, but they do not calm craving and suppress your appetite like fiber-rich foods. If you want to lose weight and move toward better health, consider eating like nature intended - by adding more fiber to your diet in the form of unrefined plant foods from sources such as beans and legumes, vegetables, fruits and grains.
If you have any questions about cutting out processed foods and adding more fiber to your diet, or if you have any medical condition, be sure to talk to your health care practitioner for more information.
Greger, M. (2019). How not to diet: the groundbreaking science of healthy, permanent weight loss. New York: Flatiron Books.
Halnes, I., Baines, K., Berthon, B., Macdonald-Wicks, L., Gibson, P., & Wood, L. (2017). Soluble Fibre Meal Challenge Reduces Airway Inflammation and Expression of GPR43 and GPR41 in Asthma. Nutrients, 9(1), 57.
Howarth, N. C., Saltzman, E., & Roberts, S. B. (2009). Dietary Fiber and Weight Regulation. Nutrition Reviews, 59(5), 129–139. as cited in (Greger, 2019).
Mcrorie, J. W. (2015). Evidence-Based Approach to Fiber Supplements and Clinically Meaningful Health Benefits, Part 1. Nutrition Today, 50(2), 82–89.
Quagliani, D., & Felt-Gunderson, P. (2016). Closing America’s Fiber Intake Gap. American Journal of Lifestyle Medicine, 11(1), 80–85.