Why adding fiber to your diet can improve overall health
For most people, the word “fiber” conjures up ideas about bowel movements and eating prunes, but fiber is about much more than regularity. While fiber can aid in relieving constipation, the benefits of consuming fiber extend well beyond simply improving digestion. Increasing your fiber intake can have a significant impact on overall health, including preventing and reducing the risk for diseases such as heart disease, type 2 diabetes, diverticular disease, and colon cancer, to name a few.
What exactly is fiber? Fiber is defined as a non-digestible carbohydrate that contains physiological benefits. While carbohydrates typically break down into glucose in the body, fiber does not, and instead passes through the body undigested. Fiber is typically classified into two types: soluble and insoluble. Both types of fiber, soluble and insoluble, are beneficial. Both are fermented in the colon, and both increase stool weight making it easier to pass through the colon. Soluble fiber dissolves in water, causing it to have gel-forming properties in the intestine. It lowers cholesterol and blood glucose levels, and is found in foods like bananas, brussels sprouts, and legumes. Insoluble fiber is associated with laxation due to its role in helping move food through the digestive tract, much like a brush sweeping through the intestines, and is found in foods like broccoli, apples, avocado and whole grains. All of these foods contain both types of fiber but are typically higher in one type than the other. More high-fiber foods with their typical serving sizes are listed below:
raspberries (4 g per half cup)
blackberries (4 g per half cup)
almonds (4 g per one ounce or ¼ cup)
flax seeds (4 g per two tablespoons)
chia seeds (11 g per two tablespoons)
Some fiber-rich foods contain prebiotics, which feed the probiotics, or the “good bacteria” in the gut, and include foods like onions, garlic, artichokes, asparagus, soybeans, and dandelion greens. While not all fiber is prebiotic, all prebiotics are fiber. The difference is that prebiotics specifically alter the gut flora, which offers health benefits including immune and digestive support. While more research is needed, preliminary studies suggest that prebiotics provide the following benefits: promote satiety and weight loss, prevent obesity, lower risk factors for cardiovascular disease, enhance the absorption of minerals (calcium, magnesium, iron), prevent colon cancer, reduce inflammation and symptoms from inflammatory bowel disease, and reduce the risk of infectious and antibiotic-associated diarrhea.
High-fiber diets have also been shown to reduce the risk of cardiovascular disease and coronary heart disease by reducing LDL cholesterol, C-reactive protein levels (associated with inflammation), and blood pressure – all biomarkers for heart disease. Furthermore, soluble fiber has been shown to reduce blood lipids. Other benefits of high-fiber diets include lowering cholesterol, enhancing mineral absorption (calcium and magnesium), and increasing satiety.
High fiber intake also reduces the risk of developing type 2 diabetes, and can lower blood sugar levels for those who already have type 2 diabetes. Because fiber is a non-digestible carbohydrate, it doesn’t spike insulin the same way that other carbohydrates do. Fiber also reduces the glycemic index of foods which leads to lower blood glucose levels.
Another advantage of a high-fiber diet is appetite control. Researchers believe that because soluble fiber binds water and therefore expands, it triggers feelings of satiety. Furthermore, fiber slows gastric emptying as well as the rate of glucose absorption in the gastrointestinal (GI) tract. As food moves through the GI tract, satiety-related hormones are released, contributing to those feelings of fullness. These gut hormones, such as ghrelin and glucagon-like peptide, regulate food intake and energy balance. Some prospective cohort studies show that people who eat high-fiber diets weigh less than their low-fiber diet counterparts. This makes sense given that fiber can reduce appetite and therefore result in a lower intake of calories.
So how much fiber is needed? The Institute of Medicine (IOM) set the recommended daily amount (RDA) of fiber to 38 grams per day for men under 50, and 25 grams per day for women under 50. For those over 50, the recommended amount for men is 30 grams daily and for women is 21 grams daily. Most Americans take in about half of what they should be consuming.
In some cases, such as with high-protein, low-carb diets, fiber intake may be low. Ideally, most fiber consumed would come from diet due to the added benefits of obtaining more nutrients from whole foods. Fiber is particularly high in whole grains and legumes, both of which are higher-carbohydrate foods that we typically do not recommend on a low-carb weight loss program. This is why we recommend eating at least four cups of vegetables per day. For those who don’t get enough fiber from foods, or for those who suffer from constipation, fiber supplements such as Garden of Life’s Acacia Fiber are a good option due to the prebiotic fiber content, or Yerba Prima Daily Fiber Caps for individuals who prefer capsules over powder.
To determine how much fiber is in a packaged food, check the Nutrition Facts label. Remember that fiber is a non-digestible carbohydrate, which is why we count net carbohydrates rather than total carbohydrates when on a low-carb weight loss program. Net carbohydrates are calculated by subtracting the grams of fiber from total carbohydrates. (Note: Sugar alcohols are also subtracted from total carbohydrates to get net carbs because they’re low-digestible carbs.)
Some examples of fiber found on the ingredients list of packaged foods, herbal teas, and supplements include guar gum, acacia gum, wheat dextrin, resistant starch, inulin, chicory root, polydextrose, pectin, beta-glucans, cellulose, hemicellulose, psyllium, gum arabic, and lignin.
To increase fiber intake, start gradually. Increasing fiber too quickly can cause gastric distress, so start by adding five grams per day for a few days at a time. To do this, simply add one serving of a high-fiber food per day, such as a half cup of broccoli at dinner. Consume a variety of vegetables in order to get all forms of fiber into your diet. Make sure to drink plenty of water to help flush the fiber through your system. Also, eat small amounts of fiber throughout the day rather than overloading your system by trying to get it all in at one meal.
In summary, most everyone – not just those who suffer from constipation – benefits from a high-fiber diet due to the reduction and prevention of diseases like type 2 diabetes, cardiovascular disease, and colon cancer. Additional benefits include a reduction in appetite, weight loss, and healthy weight maintenance. In order to get the Recommended Daily allowance (RDA) of 25 to 38 grams, try using a food tracker app like MyFitnessPal to see how much you’re getting, and how much you may need to increase. Remember to gradually increase by a few grams every few days to prevent gas and bloating. The same goes for consuming fiber throughout the day; do not try to take in the recommended daily amount in one sitting. Some people, such as those with diverticulosis, IBD, and irritable bowel syndrome (IBS) may need to lower their fiber intake during a flare-up and should discuss with a healthcare practitioner before increasing. If you have constipation that is not relieved by the recommended amount of fiber, you may need to increase your water intake, and discuss your options with your doctor. It is always more beneficial to get your fiber from whole foods, although supplements can help.
Now that you understand the many benefits of fiber, try adding just one additional fiber-rich food to your diet. Ask us about our Chia Seed Pudding recipe for a tasty treat.