Adults need dietary fiber to promote health and improve digestion, but most people don't get enough. It's recommended that female adults receive between 22 and 28 grams (g) of fiber per day and male adults get 28 to 34 grams.1
U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. 9th Edition.
Focusing on eating foods that are higher in fiber can help. Fiber supplements may also be appropriate for some people. Getting fiber from food is preferred because food also contains important vitamins and minerals.
This article will cover the guidelines for how much fiber people should eat every day, foods that can help them meet those fiber goals, and the health effects of not having enough fiber in the diet.
Daily Recommended Fiber Chart
In general, it's recommended that people get 14 grams of fiber per 1,000 calories of food they eat.2 For anyone eating around 2,000 calories, that would be 28 grams of fiber a day, which would meet most recommended daily requirements.2
Unfortunately, most people don't find it easy to get the recommended daily fiber intake. In fact, about 90% of women and 97% percent of men don't eat the recommended amount of fiber daily.1 Fruits and vegetables are a good source of fiber, but 85% of adults don't eat the recommended daily amount.
These two statistics seem to suggest that people are not eating enough of the types of fresh foods that would help them achieve a diet that meets fiber goals.1
The amount of fiber intake per day per sex and age group, as recommended by the Department of Agriculture (USDA), is shown in the following chart.1
Daily Fiber Recommendations | ||
Age (years) | Daily Calories | Daily Fiber (g) |
Females | ||
2-3 | 1000 | 14 |
4-8 | 1200 | 20 |
9-13 | 1600 | 25 |
14-18 | 1800 | 31 |
19-30 | 2000 | 34 |
31-50 | 1800 | 31 |
51+ | 1800 | 28 |
Males | ||
2-3 | 1000 | 14 |
4-8 | 1200 | 17 |
9-13 | 1600 | 22 |
14-18 | 1800 | 25 |
19-30 | 2000 | 28 |
31-50 | 1800 | 25 |
51+ | 1800 | 22 |
A Note on Gender and Sex Terminology
Verywell Health acknowledges that sex and gender are related concepts, but they are not the same. To accurately reflect our sources, this article uses terms like “female,” “male,” “woman,” and “man” as the sources use them.
Benefits of Dietary Fiber
The reason why there's such a focus on getting the right amount of daily fiber is because it has so many benefits for overall health.
An extensive meta-analysis of 185 studies found that people who ate the highest level of fiber (between 25 and 29 g) were less likely to have certain conditions than those who ate the lowest amount of fiber. The decrease in the conditions that were tracked was anywhere from 15% to 30%. Some of the conditions included:3
Eating a variety of foods high in fiber also affects the gut microbiome (the community of microbes that live in your gut). A high-fiber diet may help with colon health and increase the diversity of the microbiome.4
Chronic constipation may also improve through an increase in dietary fiber. However, this is not true for every person who has constipation. Guidelines are somewhat vague on how much fiber to use or which type. For constipation, it's thought that soluble fiber (which dissolves in water to form a gel) may be more helpful than insoluble fiber (which stays intact through your digestive tract, adding bulk).
People who experience ongoing constipation may wish to work with a healthcare provider to find the amount and type of fiber that can help while avoiding potential symptoms such as bloating.5
There's evidence that eating a higher-fiber diet may help lower the risk of colon cancer. There's less evidence for other types of cancers. However, eating more whole grains (which have higher fiber content than refined grains) may help lower the risk of other cancers.6
Increasing the amount of fiber in the diet may also help lower blood cholesterol levels.7 In particular, low-density lipoprotein (LDL) cholesterol levels might decrease with more fiber in the diet.8
Fiber may help people feel full after eating, which could lead to eating less overall and promote weight loss.9
Effects of Too Little Fiber
A low amount of fiber in the diet could lead to some health effects.
Diet can significantly affect digestion. For some people, too little fiber in the diet could lead to constipation (hard stools that are difficult to pass). For others, the result could be diarrhea (loose, watery stools). Fiber can bulk up stool and make it softer, which can help prevent constipation and diarrhea.10
High-fiber foods may take longer to digest and help people feel full longer after eating. This could, in turn, help with eating fewer calories overall. Over time, this could result in maintaining a beneficial weight for health.9
Many studies on fiber look into how increasing fiber intake affects health. Some of these studies compare people who eat lower and higher amounts of fiber and how it affects the risk of certain disorders.
Lower amounts of fiber may lead to an increase in the risk of certain conditions, such as colorectal cancer, coronary heart disease, stroke, and type 2 diabetes when compared to people who have a higher intake.3
How to Up Fiber Intake
After understanding how important fiber is to health, some people may want to increase their fiber intake. That can include adding more fibrous foods to the diet or taking fiber supplements. Fiber is found in plant-based foods, including fruits, vegetables, seeds, nuts, and whole grains.
Fiber should be gradually added to the diet over time to decrease the potential for side effects such as intestinal bloating and gas.
Here are some foods that are higher in fiber:
- 1 cup of cooked lentils: 15.6 g11
- 1 cup of cooked split peas: 8.3 g12
- 1 cup of cooked black beans: 15 g13
- 1 cup of cooked pinto beans: 15 g14
- 1 cup of cooked kidney beans: 11 g15
- 1 cup of cooked edamame: 5.2 g16
- 1 cup of cooked chickpeas: 12.5 g17
- 1 ounce of dried chia seeds: 9.8 g18
USDA FoodData Central. Seeds, chia seeds, dried.
- 1 medium apple with skin: 4.8 g19
- 1 cup of raspberries: 9.8 g20
- 1 avocado: 13.5 g21
Fiber supplements are another way to increase fiber intake. However, not every type of fiber will work for every person. It may be necessary to try different types of fiber supplements to learn which one works well for digestion and doesn't cause any unwanted effects.
The three types of fiber supplements have a main ingredient of psyllium, methylcellulose, or polycarbophil.
Whenever possible, the best idea is to get fiber from your diet. It's also important to read labels on fiber supplements carefully. Some formulations may have additives such as artificial sugars, which could also lead to digestive symptoms in some people.
A Word From Verywell
It’s important to gradually increase fiber over the course of a few weeks. Along with gradually increasing your fiber intake, be sure to also increase your fluid intake. Adding more fiber without more water can actually worsen constipation.
— ELIZABETH BARNES, RDN, MEDICAL EXPERT BOARD
Summary
It's important to include fiber-containing foods in the diet. This can mean eating fruits and vegetables as well as unrefined grains. Most adults in Western countries do not get enough fiber, which could increase the risk of certain health conditions.
Adding higher-fiber foods to the diet can increase fiber. Fiber should be added slowly to avoid gas and bloating. People with health conditions or conditions that restrict some foods may want to work with a healthcare provider to make a diet plan that meets all nutritional needs.
Sources:
- U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. 9th Edition.
- U.S. Department of Agriculture. How much (dietary) fiber should I eat?
- Reynolds A, Mann J, Cummings J, Winter N, Mete E, Te Morenga L. Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. Lancet. 2019;393:434-445. doi:10.1016/S0140-6736(18)31809-9
- Wilson AS, Koller KR, Ramaboli MC, et al. Diet and the human gut microbiome: an international review. Dig Dis Sci. 2020;65:723-740. doi:10.1007/s10620-020-06112-w
- Bellini M, Tonarelli S, Barracca F, et al. Chronic constipation: Is a nutritional approach reasonable? Nutrients. 2021;13:3386. doi:10.3390/nu13103386
- Gaesser GA. Whole grains, refined grains, and cancer risk: a systematic review of meta-analyses of observational studies. Nutrients. 2020;12:3756. doi:10.3390/nu12123756
- Soliman GA. Dietary fiber, atherosclerosis, and cardiovascular disease. Nutrients. 2019;11:1155. doi:10.3390/nu11051155
- Evans CEL. Dietary fibre and cardiovascular health: a review of current evidence and policy. Proc Nutr Soc. 2020;79:61-67. doi:10.1017/S0029665119000673.
- Harvard Health Publishing. Foods high in fiber: boost your health with fiber-rich foods.
- Lambeau KV, McRorie JW Jr. Fiber supplements and clinically proven health benefits: how to recognize and recommend an effective fiber therapy. J Am Assoc Nurse Pract. 2017;29:216-223. doi:10.1002/2327-6924.12447
- USDA FoodData Central. Lentils, mature seeds, cooked, boiled, without salt.
- USDA FoodData Central. Peas, split, mature seeds, cooked, boiled, without salt.
- USDA FoodData Central. Beans, black, mature seeds, cooked, boiled, without salt.
- USDA FoodData Central. Beans, pinto, mature seeds, cooked, boiled, without salt.
- USDA FoodData Central. Beans, kidney, all types, mature seeds, cooked, boiled, with salt.
- USDA FoodData Central. Edamame, frozen, prepared.
- USDA FoodData Central. Chickpeas (garbanzo beans, bengal gram), mature seeds, cooked, boiled, without salt.
- USDA FoodData Central. Seeds, chia seeds, dried.
- USDA FoodData Central. Apple, raw.
- USDA FoodData Central. Raspberries, raw.
- USDA FoodData Central. Avocados, raw.
Important Notice: This article was originally published at www.verywellhealth.com by Amber J. Tresca where all credits are due. Medically reviewed by Elizabeth Barnes, RDN
Disclaimer
The watching, interacting, and participation of any kind with anything on this page does not constitute or initiate a doctor-patient relationship with Veripeudic.com. None of the statements here have been evaluated by the Food and Drug Administration (FDA). The products of Veripeudic.com are not intended to diagnose, treat, cure, or prevent any disease. The information being provided should only be considered for education and entertainment purposes only. If you feel that anything you see or hear may be of value to you on this page or on any other medium of any kind associated with, showing, or quoting anything relating to Veripeudic.com in any way at any time, you are encouraged to and agree to consult with a licensed healthcare professional in your area to discuss it. If you feel that you’re having a healthcare emergency, seek medical attention immediately. The views expressed here are simply either the views and opinions of Veripeudic.com or others appearing and are protected under the first amendment.
Veripeudic.com promotes evidence-based natural approaches to health, which means integrating her individual scientific and clinical expertise with the best available external clinical evidence from systematic research. By individual clinical expertise, I refer to the proficiency and judgment that individual clinicians acquire through clinical experience and clinical practice.
Veripeudic.com does not make any representation or warranties with respect to the accuracy, applicability, fitness, or completeness of any multimedia content provided. Veripeudic.com does not warrant the performance, effectiveness, or applicability of any sites listed, linked, or referenced to, in, or by any multimedia content.
To be clear, the multimedia content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health providers with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any website, video, image, or media of any kind. Veripeudic.com hereby disclaims any and all liability to any party for any direct, indirect, implied, punitive, special, incidental, or other consequential damages arising directly or indirectly from any use of the content, which is provided as is, and without warranties.