At Eden's, fiber is something we're clearly passionate about and the many health benefits it offers, but how much fiber do you need in a day?
More than 90% of women and 97% of men fall short of the recommended intakes for dietary fiber. Found in nutrient-dense foods such as veggies, fruits, legumes and whole grains, fiber has been shown to play a significant role in gut health, which is a critical piece of every metabolic system — including vitamin and mineral absorption, energy regulation, immune system functioning and many other important processes.
Gut health is associated with better protection against metabolic diseases (such as obesity, insulin resistance and type 2 diabetes), cardiovascular diseases, certain cancers, and even neurological disorders. Fiber boosts gut health by acting as food for good gut bacteria, so that the latter can replicate and produce health-promoting compounds. Studies have shown that increasing fiber — whether through your diet or with the right supplements or both — can indeed alter your gut microbiome and thereby result in myriad long-term health benefits.
Why is fiber so important?
Research is proving that eating fiber — and more importantly, specific types of fiber — can greatly influence your gut microbiota, which has a direct impact on your gastrointestinal, metabolic, neurologic and overall health.
Dietary fiber is a non-digestible carbohydrate, which means it doesn’t break down into glucose. Instead, fiber travels through your gastrointestinal (GI) tract and becomes food for your gut microbiome. When you consume fiber, your gut bacteria ferment it and produce many byproducts (such as metabolites) that promote well-functioning systems.
One such set of byproducts are short-chain fatty acids (SCFAs), important signaling molecules that interact with the intestinal microbiome to increase the production of a number of key bioactives that have broad impacts on various aspects of host physiology — including promotion of the digestion of complex dietary macronutrients, production of nutrients and vitamins, defense against pathogens, and maintenance of the immune system.
When the quantity and types of SFCAs in your gut are found to be in good and varied supply, they demonstrate the ability to increase satiety (a feeling of fullness, which can aid in preventing obesity); stimulate motility and secretory activity and improve intestinal transit (reducing gastrointestinal distress); decrease hepatic glucose production; and protect against colorectal cancer and inflammation.
Beyond the gut, small amounts of SCFAs reach the circulation and can also directly affect the adipose tissue, brain, and liver, inducing overall beneficial metabolic effects.
When fermentable fibers are in short supply, microbes switch to energetically less favorable sources for growth such as amino acids from dietary or endogenous proteins, or dietary fats, resulting in reduced fermentative activity of the microbiota and SCFAs as minor end products. It’s therefore now apparent that human populations with a diet enriched in complex carbohydrates (i.e., fiber), such as the Hadza hunter gatherers from Tanzania, have increased diversity of the gut microbiota. In contrast, long-term intake of a high-fat and high-sucrose diet can lead to the extinction of several taxa of the gut microbiota.
In short, leading medical organizations now fully embrace the conclusion that feeding your gut microbiome with the right types and ratios of fiber has major implications for your health, including:
Overall better digestion and regularity
Fiber helps normalize bowel movements and maintains bowel health. Fiber helps increase the size and weight of stool while softening it, making stool easier to pass and decreasing your chances of constipation. Regular bowel movements help lower the risk of developing certain gastrointestinal diseases and hemorrhoids, as well as being linked to a decrease in colorectal cancer.
Fiber slows the rate at which your body breaks down food into glucose, which decreases your body’s insulin response to a meal. Consuming a fiber-heavy food (such as a high-fiber cereal) doesn’t cause a spike in blood sugar the way low-fiber, or “simple” carbohydrates (such as candy or white rice) do. The resulting prolonged energy release helps steady those peaks and dips in blood glucose, and also stabilizes your energy level.
Aid to weight management
Staying within a healthy weight is critical to reducing risk for (or better managing) metabolic syndrome, type 2 diabetes, cardiovascular diseases, stroke and many other diseases and disorders. Fiber helps you maintain a healthy weight due to three major effects:
Most foods high in fiber are nutrient-dense and usually have fewer calories for the same volume of food. Consuming nutrient-dense foods, along with consistent exercise, can lead to increased energy, a caloric deficit — and, in turn, weight loss.
Fiber moves slowly through your digestive system, keeping you fuller for longer compared to a highly digestible, simple carbohydrate (like a candy bar). When you consume a high-fiber meal, you simply may not be as hungry and will end up eating fewer calories.
- Fiber’s way of boosting your satiety level can help decrease your sugar cravings, important for better blood glucose and weight management.
Gut microbes control the balance of your body’s anti-inflammatory response. Chronic, low-grade inflammation is one of the most common paths to progressive diabetes because it has been linked to increased insulin resistance. Chronic inflammation is also linked to a number of other diseases (e.g., as cardiovascular disease) and cancers (e.g., colon cancer). The byproducts of fiber, such as SCFAs and other beneficial metabolites, help maintain a strong intestinal barrier, induce the production of protective mucus, and regulate glucose, lipid and the immune systems.
Fibrous foods can also help your body better absorb nutrients (such as calcium). Fiber has been shown to nourish microorganisms in the gut so that they continue to grow and diversify. And the more varied your gut bacteria are, the more they contribute to heightened immunity and reduced inflammation — both of which are associated with more positive health outcomes, including reduced risk of metabolic and chronic diseases (such as obesity and type 2 diabetes). Think of it this way: 70% of the body’s immune system is separated from the gut microbiome by only a single layer of microscopic cells, and gut microbes are the first line of defense against illness and disease. When the gut is in a symbiotic and healthy state, it has a positive effect on all of the other systems it interacts with.
Reduced risk for cardiovascular disease
A large body of research has associated high dietary fiber intake with lower risk of heart disease and deaths from cardiovascular disease. Aside from a lower risk of obesity and inflammation, soluble fiber intake has been linked to lower serum cholesterol levels, specifically low-density lipoprotein (LDL), or the “bad” cholesterol level deemed a major contributor to cardiovascular disease. Further, soluble fiber is thought to help reduce cholesterol levels by removing bile acids from the body. Fiber binds to bile acids in the gut and removes them as fiber is excreted. Cholesterol is a key component of making new bile acids; yet, with increased fiber intake, bile acid amounts are reduced and the liver then pulls cholesterol from the blood to rebalance new bild acid levels.
A growing body of research is now linking fiber intake to enhanced mood and cognitive functioning through the gut-brain axis (GBA), although much more research is needed on the mechanisms involved. Learn more: Can a healthier gut improve your energy levels?
Accumulating animal-based studies are suggesting that altering gut bacteria can have a direct impact on neurotransmitters that are linked with anxiety and mood disorders. In initial clinical trials, results from a randomized clinical study analyzing changes in gut microbiota and emotional mood of patients showed that with a high-fiber diet, anxiety and depression symptoms were significantly alleviated. SCFAs, the byproducts of fiber fermentation, have been shown to affect the nutrients that pass the blood-brain barrier by altering what gets through from the bloodstream. Another study focused on fiber intake and cognitive functioning, specifically regarding dementia development in 40-64 year-olds.
This 16-year study of 3,700 adults reported that the individuals who consumed the most daily fiber (20g or more per day) had the lowest rates of dementia, and those who consumed around 8g had the highest rates. The researchers believed this could be from fiber contributing to healthy metabolic markers such as weight and blood pressure, which are risk factors for vascular dementia; or, that fiber reduces brain inflammation via the gut-brain axis.
What are different types of fiber?
There are many types of fibers, some naturally-occuring and some synthetic.
Fiber is classified into categories based on how it reacts when digested: solubility, viscosity and fermentability are the primary features, with the main categories of fiber divided into ones that are soluble or insoluble. Each type of fiber provides a unique set of health benefits, so it’s important to get a variety of fibers.
If a fiber is described as viscous, it has a gel-like quality and can help control blood sugar spikes after eating. They also help you feel full. (Most viscous fibers are soluble.)
Nearly all fibers are fermentable — becoming food for gut bacteria — but some are more readily fermentable than others. The byproducts of fermentation include beneficial molecules such as SCFAs. (Nonfermentable fibers travel intact to the colon and can add bulk to your stool to make it easier to pass.) The fermentable fibers that receive the most attention in medical circles are those that are prebiotics —. a special class of fibers that are the food source for probiotics, a class of bacteria known as “good gut bacteria” that play a major role in strengthening and maintaining immune, mental, cardiac, gut, and in fact overall health. Without prebiotics, probiotics can't thrive or reproduce. To be a prebiotic, a fiber must fulfill the following criteria:
- Not digestible by mammals.
- Be fermented (i.e., digested) by microbes.
- Be able to improve activity and viability of beneficial microbes.
Soluble fiber, found in gums, pectans and fructans, dissolves in water and as it moves through your digestive tract, traps metabolic waste products (such as hormone byproducts), carcinogenic chemicals, bile, allergens and environmental toxins that need to be eliminated from the body. Soluble fiber aids in satiety as well as nutrient absorption, and is the type most known to reduce spikes in blood glucose levels and lower cholesterol. Without enough soluble fiber to remove lingering waste products, these compounds get involved in unwanted reactions and can lead to serious hormonal and gastrointestinal (GI) issues.
Insoluble fiber, such as lignin and cellulose, does not dissolve in water. These fibers travel through your digestive tract mostly intact, regulating your digestion and helping you avoid constipation. Insoluble fiber absorbs fluid and adds bulk to your stools, making bowel movements more regular and easily passed. Insoluble fiber also slows down the digestive process, helping you avoid constipation and achieve digestive regularity.
How much fiber do you need in a day?
The USDA 2020-2025 Dietary Guidelines for Americans and American Diabetes Association recommend 14g of dietary fiber for every 1,000 calories per day, which is typically between 30-40 grams of fiber per day. The quick reference based on caloric recommendations for gender and age group are as follows:
Ages 19 to 30: 28 grams
Ages 19 to 30: 34 grams
Ages 31-50: 25 grams
Ages 31-50: 31 grams
Ages 51+: 22 grams
Ages 51+: 28 grams
* Pregnant and breastfeeding women should match their fiber intake throughout each trimester of pregnancy and when breastfeeding, as their caloric needs fluctuate.
As with protein consumption, it’s best to consume fiber evenly throughout the day to help with satiety and insulin regulation. If you’re starting to increase your fiber intake, it’s best to do it slowly and with plenty of fluids. A sudden surge in fiber can cause gas, bloating or even constipation. Fiber acts as a sponge in the body and without plenty of fluids, it won’t move through easily.
Because it can be challenging to incorporate enough food fibers into your daily diet, certain newly developed fiber supplements (see end of next section) may prove advantageous.
The best high fiber foods
On a nutrition label, dietary fiber isn’t broken out by viscosity, solubility or fermentability — so eating a variety of high-fiber foods such as fruits, vegetables, whole grains, and nuts and seeds is the best way to capture as many sources of necessary fibers as possible.
You can find the amount of dietary fiber in non-packaged goods, such as produce, by checking a reliable internet source. By law, a food labeled as a “good source of fiber” must contain at least 2.5 grams of fiber per serving; and foods that are an “excellent source of fiber” must have more than 5 grams of fiber per serving.
But take care when selecting fiber; some fiber types actually make it harder for you to get nutrients. For example, cereal-derived fibers, while typically a great source of iron, zinc and calcium, may also contain factors (e.g., bran) that make it harder to absorb those nutrients. The best way to avoid encountering this is to eat a wide variety of nutrient-dense, high fiber foods, such as:
Vegetables: acorn and butternut squash, collard greens, kale, broccoli, carrots, spinach, brussels sprouts, green beans, sweet potatoes, and asparagus
Fruits: avocado, raspberries and blackberries, pears, kiwi, pomegranate, and citrus, such as oranges and tangerines
Beans and legumes: chickpeas, lentils, green peas, edamame, as well as many kinds of beans, such as kidney, black, pinto, and navy
Whole grains: bulgur, kamut, pearl barley, quinoa, buckwheat
The best high fiber supplements
If you’re concerned about not getting enough fiber in through your diet, consider a supplement. Eden’s synbiotic blend contains 8g of fiber per serving — a high percentage of your recommended daily intake. Eden’s five carefully selected fibers provide a precise ratio of soluble and insoluble fibers, in order to optimally fuel the growth of specific gut bacteria responsible for increasing the production of beneficial secondary metabolites.
In addition, Eden’s contains four probiotics and five polyphenols. The overall blend of ingredients in Eden’s has been formulated to give your good gut microbes everything they need to thrive.
3-in-1 Synbiotic Superblend
Tips on how to increase daily fiber intake
Start off right: For breakfast, start off with a high-fiber cereal, bread or add a few tablespoons of wheat bran or Eden’s to a smoothie. Opt for foods labeled with "whole grain," "bran," or "fiber" in the name.
Switch to whole grains: Make sure your flour and grain ingredients are labeled as “whole,” with at least a few grams of dietary fiber per serving. As examples, go for high-fiber crackers, swap white rice for brown, or swap half of your regular pasta for whole wheat pasta.
Find opportunities for “add-ins”: Flax seeds, chia seeds, pumpkin seeds, unsweetened dried coconut pieces, nuts, and legumes (e.g., edamame) can make great add-ins or toppings to any meal. Make sure to have a variety, and don’t over-do it: these nutrient-dense foods are also high-calorie.
Snack on more fruits and veggies: They are high-fiber and nutrient-dense. Try dipping an apple in yogurt or eating sliced vegetables with hummus.
Dietary fiber is an essential part of maintaining digestive, metabolic, cardiovascular, and even mental health, but how much fiber you need in a day can be confusing for some. The byproducts created from consuming fiber help build and maintain a well-functioning system that impacts nearly every bodily reaction.
The bottom line: it’s important to consume all types of fiber and to maximize their range of benefits; in other words, it’s best to consume a wide variety of fiber-rich foods. If you’re concerned that you may not be getting enough or the right amount of fiber, talk to your medical provider about whether you’d be a good candidate for supplementing your daily diet with a scientifically-validated product, such as Eden’s.