The content of fiber in a diet is given considerable importance at present because of its numerous benefits. A high fiber diet is ideal for a diabetic diet and it is heart friendly owing to its cholesterol-lowering properties. If you want to lose some weight in a healthy manner, fitness experts often advise to include more of fiber-enriched vegetables and fruits, beans and lentils. In addition, a diet in high fiber guards against cancer, kidney stones, constipation and gut issues, PMS and so on.
What is actually meant by fiber in a diet? What is the recommended amount of fiber? What are the best sources of high fiber food items? How to gauge the fiber content of canned food? What are the benefits of fiber in our diets and how much is too much? To know the answers to all these question marks, read on.
The definition of fiber in a diet
Dietary fiber is defined as the roughage or the indigestible food from a plant source. Mainly of two types, the soluble and insoluble one, the dietary fiber changes the consistency of the gut content in addition to the number of nutrients absorbed from the gut.
The fiber from plant sources is usually a mixed variety containing either type.
The soluble variety of the fiber is readily dissolved in water and is fermented into gas and other physiologically active byproducts. The soluble fiber delivers a filling effect.
The insoluble variety usually delivers a non-bulking effect, being insoluble in water and is responsible for the removal of water thereby easing defecation.
A high fiber diet is defined as the “one that meets or exceeds the dietary reference intake for dietary fiber, a figure set by Institute Of Medicine of the National Academy Sciences”.
The Dietary Reference Intake of Fiber
Less than five percent of the US citizens consume their requisite amount of fiber per day and an average American takes less than 14 grams of dietary fiber every day. The fact that many metabolic diseases are on the rise presently is due to the fact that our diets lack the necessary fiber, comprising mainly of processed food and food derived from animal sources.
According to the Institute Of Medicine, some of the recommended figures for dietary fiber intake are
- children age 1-3 years: 19 grams
- children age 4-8 years: 25 grams
- men age 14-50: 38 grams
- men age 51 and older: 30 grams
- girls age 9-18: 26 grams
- adult women age 19-50: 25 grams
- women age 51 and older: 21 grams
- pregnant women: 28 grams
- breastfeeding women: 29 grams
According to the Dietary Guidelines for Americans 2010, a 1000-calorie diet should contain 14 grams of fiber. A high fiber granola bar containing five grams of fiber would deliver 14% of the daily requirement.
Benefits of a high fiber diet
A high fiber diet is usually celebrated for weight loss, an outcome that is, in fact, a side effect of this particular diet. The many health benefits originate from such properties of fiber as increasing the bulk, softening the stool and shortening the transit time through the gut. Some of the worth mentioning benefits of high fiber diet is attributed to
- helps satisfy satiety by increasing the volume of food without raising the caloric count
- the soluble variety attracts water, delays gastric emptying and screens the carbohydrates from digestive enzymes, thereby maintaining the glucose absorption at a steady rate
- the soluble variety helps lower the total cholesterol levels
- the insoluble variety accelerates the passage of gut contents thus facilitating defecation
- the insoluble variety also adds bulk to stool, thereby relieving constipation
- the anti-constipating effects in addition to Ph balancing act of the fiber help protect against colon cancer
- fiber does not affect the absorption of vitamins and minerals, rather may improve the calcium incorporation
The common and verified observations about dietary fiber thus contribute towards struggle against conditions like obesity, heart disease, diabetes, and cancer. The effects of a high fiber diet in lowering cholesterol are particularly important in the prevention of coronary heart disease. The soluble fiber binds the excess of cholesterol and flushes it out from the body. In fact, The American Heart Association recommends a high fiber diet to keep the cholesterol in check and prevent heart disease.
By keeping constipation in check, fiber wards away hemorrhoids and diverticulitis, some of the very painful conditions of the gut. The sugar equilibrium maintained by fiber on accounts of decreased absorption of glucose and steady secretion of insulin from the pancreas (in response to steady blood glucose) is vital to the management of diabetes.
Best sources of dietary fiber
Regardless of the type of fiber neither is absorbed, the soluble one becomes a gel and the insoluble remains almost unchanged but both of them deliver their functions effectively, i.e. reducing the glucose absorption and bulking up of the stools respectively. Vegetables are good sources of both types; some of the other sources are fruits, nuts, beans, and lentils.
- split peas contain 16.3 grams of fiber per cup when cooked
- lentils contain 15.6 grams per cup when cooked
- black beans deliver 15 grams when cooked
- artichokes contain 10.3 grams per medium when cooked
- peas deliver 8.8 grams per cup when cooked
- a cup of boiled broccoli contains 5.1 grams
- raw raspberries contains 8 grams per cup
- raw blackberries contain 7.6 grams per cup
- avocados 6.7 grams, half and raw
- pears 5.5 grams, raw
- bran flakes contain 7 grams per cup, raw
- whole wheat pasta 6.3 grams per cup, cooked
- cooked oatmeal 4 grams per cup
- flaxseed meal 3.8 grams of fiber per two tablespoon
- chia seeds 5.5 grams per tablespoon
- quinoa 5.2 grams of fiber per one cup, cooked
- almonds 11.6 grams of fiber per cup
- walnuts 7.8 grams of fiber per cup
- chickpeas 12.5 grams of fiber per cup, cooked
- turnips 4 grams of fiber per cup
Fiber content of canned and processed food
Different countries have different labeling criteria for fiber. In the US, food manufacturers are required to indicate specifically the amount of fiber on the product. A ‘high fiber’ label indicates that there are at least five grams of fiber per serving (Whole Grains Council).
According to the Whole Grains Council, the whole grains contain one and a half to three grams of fiber per serving. This requires the manufacturers to introduce resistant starch, cellulose, lignin, bran and other fibers to a whole-wheat bar to reach five-gram fiber content.
Considerations while taking a high fiber diet
Fiber in your diet is an important component to maintain the gut functionality at optimal and avoiding constipation or diarrhea.
If you decide to take up a diet high in fiber, then there are some rules to follow
- Add it slow
New to fiber, it could add some uncomfortable events in your gut like gas, bloating, cramping, or diarrhea. No need to be discouraged, however, spacing out the total portion over the 24-hour period could help you avoid them.
“Spreading out your fiber intake throughout the day will allow you to avoid some of the gastrointestinal discomforts that a large amount of fiber may present,” says Dr. Turner-McGrievy.
- Gradually build up the dose
Even if you have committed to eating healthy after all these years, your gut would require some time to get used to the effects of fiber.
“This will decrease some of the digestive side effects you see with a sudden increase”, Dr. Turner-McGrievy says.
Gradually building up the dose in about two weeks will not only help the gut physiology to keep functioning at optimum but it will also help you to follow the symptoms and act accordingly. If you encounter any discomfort, there is no need to add more fiber as yet.
- Take plenty of water
“We need to make sure we drink an appropriate amount of water along with our fiber intake to allow for proper digestion,” says Dr. Turner-McGrievy. The problem with fiber is that it needs ample water in order to deliver any results otherwise, it will block the gut. The soluble one becomes a viscous gel while the insoluble one moves along the gut with water, any insufficient amount of water would simply deliver a plugging effect and make the symptoms worse.