The different types of fiber
Table information from references [1] and [2].
According to the Canadian Digestive Health Foundation, the following are recommended daily intakes of all types of fiber [3]:
Based on daily fiber values of 38 grams for men and 25 grams for women, most Canadians are only reaching half these amounts [3]!
How to get more fiber in your diet [4]:
Eat at least 3 servings of vegetables and 2 servings of fruit per day. One serving is equivalent to 1/2 cup of raw fruits or vegetables, or 1 cup of leafy greens
Consume legumes (beans, lentils and peas) at least 3 times per week
Snack on fruit, nuts and seeds
Have whole grains instead of refined (white flour, pasta, bread and rice)
Look at nutrition labels when buying packaged foods. They should have at least 5 grams of fiber per serving.
A few examples of foods and their fiber amounts:
Table modified from [5]. Visit the link in the references section for a more comprehensive list.
It would be preferable to get fiber from whole foods but if this is not possible, supplements are an option. Keep in mind that not all fibers are created equal and it’s important to know which have clinical evidence behind them for specific health benefits. Based on research, here are some tips for choosing the right fiber [6]:
Fibers that lower cholesterol and blood sugar [6]: viscous soluble gel forming fibers taken with meals. These include beta-glucans (such as in oats and barley) and psyllium.
Reduce cholesterol levels by trapping bile, a fluid made in the liver and stored in the gall bladder which breaks down fats. By trapping bile, this interferes with its reabsorption into the body and instead bile gets eliminated in stool.
Improve glycemic control by increasing the thickness of chyme, the fluid with partially digested food that goes from the stomach to the small intestine. The increased thickness slows digestion and absorption of nutrients including glucose.
Fibers that promote bowel regularity [6]: coarse wheat bran and psyllium
Psyllium contains 70% soluble and 30% insoluble fiber [7]. It remains unfermented as it passes intact through the digestive system and it absorbs water making stool bulkier and softer. Both these properties aid bowel regularity [6].
Wheat bran is an insoluble fiber that irritates the digestive system because it is coarse, causing secretion of mucous and water for easier passage of the stool [6].
It’s important not to overload your system with too much fiber as it can lead to uncomfortable gas, bloating and abdominal cramps. It may be better to gradually introduce more fiber and see how the body reacts. Also, make sure to hydrate (8 glasses of water per day) especially if you are taking psyllium because it absorbs water and could make constipation worse if not taken properly.
This post is for educational purposes. Speak to your healthcare provider for advice on how you can incorporate more fiber in your diet.
References:
1. Soluble and insoluble fiber: what is the difference? Medical News Today. Accessed from:https://www.medicalnewstoday.com/articles/319176.php
2. Dr. Lander. Lecture 1D – Fiber. Canadian College of Naturopathic Medicine. Delivered in 2016.
3. Recommended Daily Fiber Intake. Canadian Digestive Health Foundation. Accessed from https://cdhf.ca/health-lifestyle/recommended-daily-fibre-intake/
4. How to get more fiber in your diet. Harvard Health Publishing. Accessed from https://www.health.harvard.edu/staying-healthy/how-to-get-more-fiber-in-your-diet
5. Food Sources of Fiber. Dietitians of Canada. Accessed from: https://www.dietitians.ca/Downloads/Factsheets/Food-Sources-of-Soluble-Fibre.aspx
6. McRorie, J.W. and McKeown, N.M. 2016. Understanding the Physics of Functional Fibers in the Gastrointestinal Tract: An Evidence-Based Approach to Resolving Enduring Misconceptions about Insoluble and Soluble Fiber. Journal of the Academy of Nutrition and Dietitics. 117(2): 251-264. https://www.ncbi.nlm.nih.gov/pubmed/27863994
7. Moreno, L.A., Tresaco, B., Bueno, G., Fleta, J., Rodriguez, G., Garagorri, J.M. and Bueno, M. 2003. Psyllium fiber and the metabolic control of obese children and adolescents. Journal of Physiology and Biochemistry. 59(3):235-242. https://www.ncbi.nlm.nih.gov/pubmed/15000455