Fiber, or rather dietary fiber, comprises the parts of plant foods that the body can neither digest nor absorb. It is also known as roughage or bulk and unlike the rest of the food components such as carbohydrates, proteins, and fats, the dietary fiber is not broken down or absorbed by the body. Instead, it passes through the stomach, small intestines, colon and finally out of your body in a relatively intact state. It is found mainly in fruits, legumes, leafy green vegetables and whole grains (1).
Dietary fiber is found in two forms: soluble dietary fiber and insoluble dietary fiber. Soluble fiber usually forms a gel-like substance which slows down the passage of food through the digestive tract to allow proper absorption of nutrients by dissolving in the water in the body’s digestive system. Insoluble fiber acts as bulk in the food by encouraging the food to pass more quickly through the digestive tract. Dietary fiber has a lot of health benefits some of which will be focused on below.
Health Benefits of Fiber
1. All Natural Detox
With dietary fiber in your diet, you do not need to worry about a juice cleanse anymore. The dietary fiber is a natural detoxifier which scrubs and gets rid of toxins from the gastrointestinal tract. The soluble fiber does this by soaking up the compounds which are potentially harmful like the unhealthy fats and excess estrogen before the body absorbs them. The insoluble fiber lessens the amount of time that the harmful chemicals like mercury, BPA, and pesticides are in contact with the intestines by passing them through the digestive tract quickly (2).
Bottom Line: Dietary fiber helps to get rid of toxic compounds in the food in a natural manner with the soluble and the insoluble fiber each playing different roles towards that.
2. Blood Sugar Control
Fiber also plays a role in the control of blood sugar. Soluble dietary fiber helps in blood sugar control by slowing down the breakdown of carbohydrates and sugar absorption. This also helps reduce the risk of diabetes since if one eats lots of sugary stuff, there occurs sudden sugar spike which can wear out the insulin production and consequently increase the risk of diabetes (3).
Bottom Line: Dietary fiber helps control the blood sugar level and reduce the risk of diabetes.
3. Healthier Bones
It has been proven that some types of particular soluble fiber upsurge the bioavailability of minerals such as calcium in the diet you take (4). Calcium is an important mineral for bone health and helps to maintain a good bone density. These soluble fibers are sometimes referred to as prebiotics and are found in leeks, soybeans, oats, wheat, and asparagus (2).
Bottom Line: Dietary fiber known as prebiotics increase bioavailability of calcium which is vital for maintaining healthy bones.
4. Healthier Gut Bacteria
The good bacteria that live in the gut feed on fiber to survive. As the good bacteria eat up the fiber that has been fermented in the gastrointestinal tract, short-chain fatty acids are produced. These short-chain fatty acids have a lot of benefits such as reducing systemic inflammation, a condition which has been associated with obesity and almost all the chronic health problems. A good intake of fiber is therefore linked with higher levels of short-chain fatty acids. A change in the diet with regards to fiber contents produces almost immediately observable results within just a few days (5). However, to keep enjoying the benefits, one needs to be consistent in a healthy dietary fiber intake. Hold back on fiber intake shifts the population of the bacteria in a way that increases the inflammation in the body.
Bottom Line: Good bacteria living in the gut feed on dietary fiber and prevent inflammation in the body.
5. Longer Life in General
Studies have shown that dietary fiber not only helps in living a healthy life but also promotes longevity (6). A study, for example, found out that people who often ate whole grains and cereals rich in fiber had a reduced risk of death from any cause by 17% and 19% respectively compared to those who ate less fiber-heavy food (2). Therefore, feeding on foods rich in fiber can increase your longevity or give you a longer life. This is also supported by the fact that fiber intake reduces the risk of death from cardiovascular disease, respiratory disease or infectious disease. A high intake of fiber is also associated with fewer cancer deaths in men.
Bottom Line: The dietary fiber has been proven to increase the length of life coupled with the fact that dietary fiber reduces the risk of deaths from a myriad of diseases.
6. Lower Risk of Heart Disease
A review of 22 studies which were published in the British Medical Journal found out that your risk of heart disease drops by 9 percent for every 7 grams of fiber that you eat per day. This is in part due to the ability of the dietary fiber to soak up the excess cholesterol in the system and get rid of it before it can start clogging the arteries (2). It binds with the cholesterol particles in the digestive system and removes them from the body before they are absorbed (7).
Bottom Line: The dietary fiber assists the body to avoid heart diseases by preventing excess cholesterol from clogging up the arteries.
7. Lowering of Cholesterol Levels
LDL cholesterol or the bad cholesterol is reduced by about five percent if one increases their daily dietary fiber intake by 5-10 grams as research has shown. Fiber can reduce the amount of bad cholesterol by reducing the amount of bile which is reabsorbed back into the intestines. When the fiber interferes with the reabsorption of bile into the body, it is usually removed from the body alongside the feces. To compensate this bile loss, more bile salts have to be made by the liver. Bile salts are made by the body using cholesterol and therefore to get the cholesterol it needs to make more bile salts, production of LDL receptors by the liver is increased. These receptors are the ones which pull out the cholesterol from the LDL molecules in the blood. There is also a possibility that one of the short-chained fatty acids produced when soluble fiber ferments restricts the amount of cholesterol that the liver produces (8).
Bottom Line: Dietary fiber interferes with the reabsorption of bile in the intestines which necessitates the production of more bile salts. The production of the bile salts requires cholesterol and thus it is reduced in the process.
8. Maintenance of Bowel Health
Dietary fiber has been associated with digestive system health for long. It helps the digestive tract to operate more speedily and efficiently. This improves the health of the colon which may help prevent inflammation of the polyps or development of small pouches in the colon –a condition known as diverticulitis. It can also protect the body against irritable bowel syndrome (IBS). Fiber generally improves the operation of the intestines. Soluble fiber in dried beans and other legumes, barley, oats, and berries may help to control diarrhea by slowing down the food in the gastrointestinal tract and producing the egestion in stool form. Insoluble fiber may reduce the risk of diverticulitis by 40 percent (9).
Bottom Line: Dietary fiber generally helps in maintaining the health of the bowel by preventing the inflammation of polyps.
9. Maintenance of Healthy Weight
Fiber helps you to avoid gaining weight if you already have a desirable normal weight. People with higher fiber intake tend to be leaner in general than people who are obese. A study showed that obese people got an average amount of nearly 1 gram of fiber less in a day as compared to normal weight people. Another study showed that fiber, specifically soluble fiber, helps to prevent weight gain and accumulation of body fat. Tests done on mice showed that those that were put on a diet which didn’t have soluble fiber gained weight and accumulated more body fat as compared to those who were provided with fiber. The mice which were given sufficient soluble fiber repelled accumulation of fat again even when they were put on a diet with high-fat content. This, therefore, shows that fiber helps to maintain a healthy weight and avoid accumulation of fat (2).
Bottom Line: Dietary fiber plays an important role in helping to maintain a desirable body weight. Soluble fiber, in particular, prevents weight gain and accumulation of fat even when you eat a diet with high-fat content.
10. Normalizing Bowel Movements
Dietary fiber increases the size and weight of your stool. It also makes the stool softer but solid. A massive stool is easier to pass and therefore this decreases the chances of experiencing constipation. Insoluble fiber bulks up the stool and sweeps through the bowels like a brush to make sure the tract is clean and to keep things moving. The soluble fiber absorbs water from the digestive system and forms an emollient mixture which facilitates smooth passage of the stool in the intestines. Softer and bulkier stool keeps you regular because they move more quickly through the colon and have less difficulty in passing (10).
Bottom Line: The dietary fiber helps to prevent constipation by bulking up the stool and smoothening the movement of stool in the gastrointestinal tract.
11. Prevention of Gallstones and Kidney Stones
A diet which is rich in fiber content may reduce the risk of contracting kidney stones and gallstones probably due to its ability to regulate blood sugar level (11). However, dietary intake of fiber should not be regarded as a treatment for these diseases but rather just a preventive measure. Persons suffering from kidney stones or gallstones should seek medical attention from a qualified physician to receive dietary guidance and the proper prescription for the control of either of the diseases.
Bottom Line: Dietary fiber helps in reducing the risk of contracting kidney stones and gallstones. This could be likely due to its ability to control the blood sugar level.
12. Reduces Risk of Certain Cancers
In a study that was published in the Annals of Oncology, an ingestion of every 10 grams of fiber was reported to correspond to a 10 percent risk reduction of colorectal cancer and a 5 percent drop in the risk of breast cancer (2). Apart from the ability of the fiber to fight cancer, the diet that contains fiber, mostly fruits and vegetables also contain high levels of antioxidants and phytochemicals which further play a role in reducing the risk by getting rid of cancerous compounds. In regards to this, an adequate daily intake of fiber could go a long way in prevention of cancer.
Bottom Line: Dietary fiber intake assists the body in lowering the risk of some types of cancers such as colorectal cancer and breast cancer. Foods with anti-cancer effects also contain antioxidants and phytochemicals which further reduce the risk of cancer.
13. Skin Health
Excretion of yeast and fungus from the body through the skin could trigger acne or rashes (12). Fiber and in particular psyllium husk helps to remove the yeast from the body and thus prevents the possibility of occurrence of rashes or acne caused by excretion of the yeast and fungus from the body.
Bottom Line: Fiber helps to avoid rashes and acne caused by the excretion of fungus and yeast from the body through the skin by helping in removing the yeast and fungus from the body.
It has been established by researchers that the risk of a stroke is reduced by 7 percent per every 7 grams more fiber consumed on a daily basis. 7 grams of fiber can be obtained by eating a bowl of whole grain pasta, a serving of tomatoes and an apple. The researchers say that fiber may help reduce the risk of stroke by its ability to control weight and lower the excessive cholesterol levels (13). However, different sources of fiber, as well as different types of fiber, may have different effects in the prevention of stroke. The investigation of each type and/or source of fiber and its role in the prevention of stroke is still an area of interest in research. The association between fiber consumption and stroke mortality has not yet been understood (14).
Bottom Line: Although the association of fiber consumption and the stroke mortality is not known yet, it has been established that fiber consumption and risk of a stroke are inversely related thus higher fiber consumption lowers the risk and vice versa.
15. Weight Loss
One can lose some weight even if the only dietary change they make is increasing the fiber intake. Foods which are rich in fiber help one lose weight by filling you up faster and thus preventing eating of excess food or keeping you satisfied for longer to reduce the frequency of eating. They also prevent the absorption of some of the calories found in the food eaten. The fiber binds with the sugar and fat molecules in the digestive system and generally reduces the number of calories absorbed (15, 16).
Bottom Line: Fiber helps in achieving weight loss by filling you up faster, keeping you satisfied for longer and preventing the absorption of some of the calories found in the diet.
Best Foods High in Fiber
With all the benefits which have been discussed above, it is clear that dietary fiber is of the essence to the human diet. It helps in avoidance of many diseases and also improvement of performance of the digestive system. As earlier mentioned, dietary fiber can be found in two kinds namely the soluble and the insoluble fiber. Both soluble and insoluble fiber are equally important for the health of the body since each of them has a unique and distinctive role to play. The dietary fiber is found in our diet through feeding on fresh foods rich in fiber or by taking fiber supplements. Many processed foods include fiber which has been added. However, this added fiber used to supplement the food is not the healthiest. In the contrary, just like the common fiber supplements, most of the ingredients are harmful to your health (17). Therefore, it is much more advisable to only eat fresh foods which not only contain good, healthy fiber but also contain other nutrients that you need. There are many foods which are known for fiber-richness but the following list is going to focus only on the best and less-known foods that are rich in fiber including fruits, vegetables, legumes, and beans.
The avocado is perhaps the most popular fruit and most easily available fruit in most regions. The content of fiber in the avocado depends on the type (18). The smooth skinned bright green avocados and the smaller darker avocados with dimples on the skin vary in fiber content and the make-up. The smooth skinned bright green ones have notably more insoluble fiber content than the small darker dimpled avocados. When sliced, a cup of avocados provides 10.1 grams of dietary fiber with the addition of other nutrients such as Vitamin C, Vitamin E, Vitamin B6, Vitamin K, potassium and folate (19). Apart from the fiber and the nutrients, avocados contain healthy fats and help to lower the cholesterol thus indirectly reducing the risk of heart diseases and other cardiovascular illnesses (20). It is time you started fitting in fresh avocado into your diet.
Bottom Line: Contains 10.1 grams of dietary fiber per cup of avocados alongside other nutrients such as Vitamin C, Vitamin E, Vitamin B6, Vitamin K, potassium, and folate.
2. Asian Pears
The Asian pears are sweet, crunchy and delicious. Another additional benefit about these Asian pears is that not only are they rich in the fiber content but also rich in Omega-6 fatty acids which are associated with healthy cells, nerve, and brain function. They can provide as much as 149 milligrams of Omega-6 fatty acids per serving (21). It is recommended to take at least 5-10 percent of food calories from Omega 6 fatty acid foods. A medium sized fruit with skin on can provide just about 9.9 grams of fiber (21). Additionally, it provides nutrients such as Vitamin C, Vitamin K, Omega-6 fatty acids and potassium (21).
Bottom Line: Contains 9.9 grams of dietary fiber and other nutrients such as Vitamin C, Vitamin K, Omega-6 fatty acids, and potassium.
Berries come in two types, the raspberry and the blackberry (22). Blackberries have been associated with improving bone density while raspberry supports healthy bones, skin and blood sugar levels. The blackberry is high in Vitamin K while raspberries are also each high in Manganese levels. For raspberries, a cup of raspberries provides an amount equal to 8.0 grams of fiber and the additional nutrients Vitamin A, Vitamin C, Vitamin E, Vitamin K and folate (23). Blackberries provide 7.6 grams of fiber per cup with the following minerals prominent: Vitamin C, Vitamin K, Omega 6 fatty acids, potassium, magnesium, and Manganese (24). In addition, it is another great tasting way of including fiber in the diet.
Bottom Line: Blackberry contains 7.6 grams of fiber per cup and the following notable nutrients; Vitamin C, Vitamin K, Omega 6 fatty acids, potassium, magnesium, and Manganese. Raspberry contains 8.0 grams of fiber and also provides the following nutrients in moderate amounts; Vitamin A, Vitamin C, Vitamin E, Vitamin K, and folate.
The popularity of fiber products is increasing in recent days. Coconut has a low glycemic index and is easy to be integrated into the diet. It has 4 to 6 times the amount of fiber as oat bran. Coconut flour and grated coconut is an excellent way of incorporating a healthy natural fiber into the diet. Fewer cases of high cholesterol and heart diseases have been reported in regions where coconut is a staple food. Coconut contains 7.2 grams of dietary fiber per cup with the addition of other nutrients such as Manganese, Omega-6 fatty acids, Folate and Selenium (25). When cooking, coconut flour can be used to substitute part of the other flours, about 20 percent.
Bottom Line: Coconut provides 7.2 grams of dietary fiber for each cup as well as Manganese, Omega-6 fatty acids, Folate and Selenium.
Figs are a good source of fiber both in the dried state and in the fresh state. Figs have an almost perfect balance of the soluble and insoluble fiber, unlike many other foods which tend to have one as dominant over the other. They are linked with lower blood pressure and protection against the degeneration of the macula, apart from the benefits of fiber. Fresh figs are delicious to eat for a person who doesn’t like dried figs and can be eaten on top of other meals such as cereals, salads or even stuffed with goat cheese and honey for special dessert. A cup of dried figs has 14.6 grams of fiber which is evenly distributed between soluble and insoluble fiber (26). Other prominent nutrients present in figs are pantothenic acid, potassium, Manganese, copper and Vitamin B6.
Bottom Line: A cup of dried figs provides 14.6 grams of dietary fiber and which is divided evenly between the soluble fiber and the insoluble fiber.
Artichokes are rich in essential nutrients as well as fiber. They are low in calories and a great addition to your diet. A single medium artichoke covers nearly half of the recommended daily requirement for women and a third of the recommended daily requirement for men. In addition to that, artichokes are one of the top high antioxidant containing foods. A medium artichoke provides on average 10.3 grams of fiber and Vitamins A, C, E, B, K, potassium, calcium, magnesium, and phosphorus (27). Although the hearts of the artichokes are the most widely consumed and are more readily available, the artichoke leaves are actually where most powerful nutrients of the artichoke are stored. The now common artichoke extract supplements which have become popular due to their heart health-promoting properties are mostly extracted from antioxidants and phytonutrients located in the leaves of the vegetable.
Bottom Line: A medium artichoke provides 10.3 grams of dietary fiber and also the minerals Vitamins A, C, E, B, K, potassium, calcium, magnesium and phosphorus.
Peas are full of fiber, powerful antioxidants, and phytonutrients and thus anti-inflammatory properties that support good health. Peas are ideal to incorporate into your diet since they are available in frozen form all year round. They are just lightly steamed and added to soups and salads to obtain that gentle sweetness they offer while at the same time providing almost all of Vitamin C recommended daily requirement and over a quarter of Thiamin and Folate each. A cooked cup of peas provides 8.8 grams of fiber which is majorly insoluble fiber. They also contain Vitamin K, Vitamin B6, Vitamin A, protein and Manganese (28).
Bottom Line: Contains 8.8 grams of dietary fiber per cup of cooked peas and which is mainly composed of insoluble fiber. It also provides nearly all Vitamin C required and over a quarter of the requirements of Thiamin and Folate.
Okra which is also known as “lady’s finger” or “bamia pod” is a common favorite and nutritious vegetables. Pods are usually gathered while still green, tender and still immature. The pods are rich in phytonutrients and grow well in well-drained and manure rich soil. They are among the low-calorie vegetables providing only 22 calories per 100 grams (29) and contain no saturated fats or cholesterol. Okra is a staple in the southern part of the United States and for a reason. A single cup provides for almost a third of the recommended daily fiber and is one of the top foods rich in calcium as well. It is full of many other nutrients and can be taken with soups and stew. The total dietary fiber per single cup is 8.2 grams. Other prominent nutrients include Vitamins A, C, and K, riboflavin, iron, phosphorus, zinc, niacin, thiamin, calcium and protein (29).
Bottom Line: It is one of the low-calorie vegetables with only 22 calories per 100 grams and no saturated fats or cholesterol. Total dietary fiber per single cup is 8.2 grams alongside Vitamins A, C, and K, riboflavin, iron, phosphorus, zinc, niacin, thiamin, calcium, and protein.
9. Acorn squash
Acorn squash is a variety of Cucurbita pepo, a squash species which also encompasses pumpkins and zucchini. It is a winter squash which means that it is eaten during the winter when it has fully matured. Acorn squash has an acorn-like shape with a dark green color. These winter squashes including butternut squash, pumpkin squash, spaghetti squash and acorn squashes are full of nutrients and fiber. The fleshy, bright colored part is full of nutrients and highly soluble fiber. A baked cup of acorn squash provides 9.0 grams of dietary fiber with the inclusion of other nutrients such as Vitamin C, Thiamin, potassium, Manganese, Vitamin A, Vitamin B6, Folate and magnesium (30). Acorn squash can be roasted in the oven and taken in place of white potatoes and other starches. They can also be used to make soups.
Bottom Line: Provides 9.0 grams of dietary fiber per baked cup of acorn squash. It also provides Vitamin C, Thiamin, potassium, Manganese, Vitamin A, Vitamin B6, Folate, and magnesium.
10. Brussels sprouts
Brussels sprouts are small, cabbage-like vegetables which belong to the cruciferous vegetable family, a group of vegetables which are rich in nutrients and especially important in fighting cancer (31). The Cruciferous family which is also required to as Brassica vegetables include vegetables such as cabbage, broccoli, cauliflower and collard greens which are rich sources of antioxidants that help fight diseases and other nutrients. These vegetables are also low in calories and possess anti-inflammatory properties. Brussels sprouts are used for healthy detox and they may reduce the risk of certain types of cancer. Their total dietary fiber content per cup is 7.6 grams of fiber with almost balanced levels of soluble and insoluble fiber. Other nutrients present include Vitamins C, K, B1, B2, B6, Folate, and Manganese (32).
Bottom Line: The total dietary fiber content is 7.6 grams per cup with almost balanced proportions of soluble and insoluble dietary fiber. Other nutrients provided by Brussels sprouts are Vitamins C, K, B1, B2, B6, Folate and Manganese.
11. Black beans
Black beans are full of nutrients and provide good fiber and protein to your diet. They have high levels of flavonoids and antioxidants which help to fight free radicals thus reducing the risk of some cancers and inflammatory diseases. They are a delicacy and also a rich source of dietary fiber. A single cup of black beans provides 15.0 grams of fiber with other notable nutrients present being thiamin, folate, phosphorus, Folate, Manganese, and magnesium (33).
Bottom Line: A single cup of black beans has 15.0 grams of dietary fiber and as other nutrients such as thiamin, folate, phosphorus, Folate, Manganese, and magnesium.
Chickpeas, also referred to as garbanzo beans have been around for a long time and are rich sources of essential nutrients like Manganese. These chickpeas provide for 84 percent of the daily Manganese requirement (34). Chickpea is the second most widely eaten and grown bean in the world, only second to the soybean. They help to increase satiety, improve digestion, and keep blood sugar levels in check, increase immunity and many more benefits. The chickpea is a rich package of proteins, minerals, and vitamins. The total dietary fiber content of the chickpea is 12.5 grams of fiber per cup (34). Also included are other nutrients such as proteins, copper, Folate, Manganese, Omega-6 fatty acids and Omega-3 fatty acids.
Bottom Line: This is the second most widely grown and eaten bean in the world, second to soybean. Provides 12.5 grams of fiber per cup and also nutrients like proteins, copper, Folate, Manganese, Omega-6 fatty acids and Omega-3 fatty acids.
13. Lima Beans
These are large, flat, almost white, kidney shaped seed belonging to the bean family. They are usually eaten shelled for their beans and just like the other major beans, lima is also one of the ancient cultivated crops. There are two variations of lima beans, big and small that are a result of evolution from two different genetic make-ups. They are not only a rich source of dietary fiber but also a great source of plant proteins. They provide 38 percent of the daily recommended protein intake and are also a rich source of antioxidants, vitamins, minerals and plant sterols. A single cooked cup of lima beans provides 13.2 grams of dietary fiber and also additionally copper, Manganese, Folate, phosphorus, protein, Vitamin B2 and Vitamin B6 (35). In addition to the rich supply of dietary fiber, lima beans offer 25 percent of the daily recommended iron intake for women (35). The Manganese boosts energy production and the antioxidants help to fight free radicals which would cause cancer.
Bottom Line: One cooked cup of lima beans has 13.2 grams of dietary fiber and nutrients such as copper, Manganese, Folate, phosphorus, protein, Vitamin B2, and Vitamin B6. Also, provides 25 percent of daily iron requirement for women.
14. Split Peas
Yellow and green split peas are a common ingredient used to make pea soup or otherwise known as split pea soup and sometimes called Pease pudding. They are rich protein sources and low in fat. Split peas contain one gram of fat per 350 calories serving. Most of these calories are drawn from the proteins and complex carbohydrates. It is regarded as one of the natural food sources which has some of the highest amount of dietary fiber content. A cup of cooked split peas contains 16.3 grams of fiber (36). It also contains other important nutrients such as thiamin, folate, Manganese, Omega-3 fatty acids and Omega-6 fatty acids.
Bottom Line: Is one of the natural foods sources with the highest levels of dietary fiber having 16.3 grams of dietary fiber per cup of cooked split peas. Other nutrients included are thiamin, folate, Manganese, Omega-3 fatty acids and Omega-6 fatty acids.
Lentils are an edible pulse which has the second highest ratio of protein per calorie of all legumes, only coming second after soybeans. They are especially of potential value to diabetic persons due to their low levels of readily digestible starch which is only 5 percent and high levels of slowly digested starch (37, 38). Lentils are relatively easy to prepare as compared to other types of dried beans. They absorb the flavor from other foods and seasoning readily, is a rich source of nutrients and are available throughout the year. In addition to fiber, which is 15.6 grams of fiber per cup of cooked lentils (39), they are rich in folate and are actually among the top high folate foods. Folate is particularly important for expectant women, people with liver disease and individuals under certain medication. They also contain proteins, iron, Manganese and phosphorus in moderate proportions.
Bottom Line: Are among the top high folate content foods and provide 15.6 grams of dietary fiber per cup of cooked lentils. Other nutrients provided are proteins, iron, Manganese, and phosphorus.
With all these foods providing fiber, you are left with many alternatives if you want to enjoy the benefits of dietary fiber which were discussed above. It is, however, important to appreciate the fact that diet change and inclusion of fiber cannot be taken as treatment for a specific problem unless a medical officer has instructed so. Intake of dietary fiber also needs to be accompanied by other healthy lifestyle practices to obtain best outcomes. Ensuring you eat a balanced diet is an extra step in increasing the effectiveness of the diet change. Nevertheless, the listed food are not the only sources of dietary fiber. There are other food sources of dietary fiber and the exploration above is not exhaustive, just a selection of some of the best.