Fiber

As I started learning about what role dietary intake could have on health, one of the first subjects that popped up was dietary fiber. I’m glad that this was one of the earliest topics that I came across, as it turns out to be one of the foundational building blocks that I just never quite understood or appreciated. Had I taken a quiz a couple years ago, I would have been able to fill in all of one answer to the question of what fiber does for our bodies, and I’m sure you can guess what that is. I wish I had been taught much earlier in life about the role that it plays rather than blindly living my life in a low-fiber, processed world for so long, running up the risk factors associated with the lack of this essential carbohydrate.

Here’s a little of what I learned:

First and importantly, increasing fiber is relatively easy and delicious. I had been operating under the misperception that I would have to eat bland, dry, non-descript foods in order to get the recommended daily intake of fiber. That couldn’t have been more wrong. Berries, fruit, veggies with hummus, and nuts (among many other satisfying foods) are all great sources. Eating more of all of those is both easy and delightful.

So, how much are we talking? The recommended daily amount varies slightly from institution to institution, but they’re all somewhat similar.

I drew a few conclusions from these recommendations:

  • I wanted to try to get at least 25g per day.
  • The Institute of Medicine was higher for men. Although the others were lower than the Institute of Medicine, a few of them and many other resources, mentioned that increased intake has increased benefits.
  • European and Japanese guidelines were similar to U.S. guidelines, which I always like to check due to how regional politics and conflicts of interest can often shape recommendations.

How was I doing? Not great: Breakfast, ~3 grams; Lunch, ~6 grams; Dinner, ~6 grams. Fifteen grams total. Coincidentally, this is the exact value that I had often seen quoted in literature about how much fiber the average American was consuming each day. As a child of Lake Wobegon, that simply wasn’t going to do. And, to top it off, I had always prided myself on the idea that I ate healthy meals – I nearly always made food from scratch and I always included some sort of fruit or vegetable with lunch and dinner. To find that I was at about half of the recommended value was somewhat depressing.

So, it’s somewhat depressing to find out you’re falling reasonably far below common recommendations. So what? Should I really care if I’m only getting half of what is recommended? This is the key part that I wish I would have learned earlier.

Here are some of the things that fiber has been associated with, based on a brief survey of sources:

  • Fiber feeds the microbiota in the large intestine and colon, creating short-chain fatty acids. These short chain fatty acids serve as a nutrient source for the body, aide muscle function, and play a positive role in the prevention of chronic diseases [2];
  • Prevention of dietary-induced obesity [1] and aide in attaining a healthy weight [3, 11];
  • Helps normalize plasma glucose levels, manage insulin resistance, and impact the incidence of type 2 diabetes [1, 3, 11];
  • Helps decrease LDL cholesterol [3, 11];
  • Has a positive influence on the treatment of ulcerative colitis, Crohn’s disease, and antibiotic-associated diarrhea [1];
  • Improves blood pressure control in patients with hypertension [3];
  • Possible anti-inflammatory affects [3];
  • Likely protection against colorectal cancer and breast cancer [4];
  • Increases the speed of transit of food through your digestive system, triggering the hunger satiating signals in your body more quickly, as well as delaying the emptying of the stomach, both of which reduce the desire for second/larger portions [10];
  • Softening of stools [11].

With that as a starting point of the benefits, the question became how to increase my daily intake. This turned out to be relatively easy. First off, I found that I love this breakfast bowl. While that’s a satisfying meal all on its own, sometimes I additionally eat a half of an avocado. For lunch, a salad, carrots/celery with humus, mixed nuts, and fresh fruit is a perfect combination that has enough internal and day-to-day potential for variation that it has become my daily go-to. For dinner, there are so many different options, so we try to mix it up each day, rotating through a 2-3 week variety of different meals.

Each person is different and the way and the degree to which they choose to implement will be different. As Dr. Robert Lustig puts it, fiber is half the antidote in preventing and dealing with metabolic syndrome. As I stated at the top, I’m both glad that I learned about the role and importance of fiber early in my research on food-related health, but also wish I had learned about it at a much earlier age. I just try to keep at the forefront of my mind the saying that “the best time to plant a tree was 20 years ago, the second best time is today.”

Here’s to your good health!

January 22, 2023

While the “References” section contains all the resources used in this article, the ones listed in the “Articles,” “Books,” and “Organizations” sections are ones that I found to be especially good at providing insightful overviews.

Articles

Books
Fat Chance by Robert Lustig
How Not to Die by Michael Greger and Gene Stone

Organizations
Nutritionfacts.org

References
[1] den Besten G, van Eunen K, Groen AK, Venema K, Reijngoud DJ, Bakker BM. The role of short-chain fatty acids in the interplay between diet, gut microbiota, and host energy metabolism. J Lipid Res. 2013 Sep;54(9):2325-40. doi: 10.1194/jlr.R036012. Epub 2013 Jul 2. PMID: 23821742; PMCID: PMC3735932.

[2] The Nutrition Source. The Microbiome. The Harvard T.H. Chan School of Public Health, https://www.hsph.harvard.edu/nutritionsource/microbiome/, Accessed 1/20/2023.

[3] Milagros Galisteo, Juan Duarte, Antonio Zarzuelo, Effects of dietary fibers on disturbances clustered in the metabolic syndrome, The Journal of Nutritional Biochemistry, Volume 19, Issue 2, 2008, Pages 71-84, ISSN 0955-2863, https://doi.org/10.1016/j.jnutbio.2007.02.009.

[4] Greger, Michael, and Gene Stone. How Not to Die. New York, Flatiron Books, 2015.

[5] AskUSDA. How Much (dietary) fiber should I eat?. U.S. Department of Agriculture, published November 7, 2022, https://ask.usda.gov/s/article/How-much-dietary-fiber-should-I-eat, Accessed 1/18/2023.

[6] Van Horn, Linda, and For the Nutrition Committee. Fiber, Lipids, and Coronary Heart Disease, A Statement for Healthcare Professionals From the Nutrition Committee, American Heart Association, published June 17, 1997 https://www.ahajournals.org/doi/full/10.1161/01.cir.95.12.2701, Accessed 1/21/2023.

[7] Quagliani, Diane, and Patricia Felt-Gunderson. Closing America’s Fiber Gap, Communication Strategies from a Food and Fiber Summit, published July 7, 2016, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6124841/#bibr1-1559827615588079, Accessed 1/21/2023.

[8] EFSA Sets European Dietary Reference Values for Nutrient Intakes, published March 26, 2010, https://www.efsa.europa.eu/en/press/news/nda100326, Accessed January 21, 2023.

[9] Overview of the Dietary Reference Intakes for Japanese (2020), https://www.mhlw.go.jp/content/10900000/000862500.pdf, Accessed January 20, 2023.

[10] Lustig, Robert. Fat Chance. New York, Hudson Street Press, 2013.

[11] Mayo Clinic Staff. Healthy Lifestyle, Nutrition and Healthy Eating. Dietary Fiber: Essential for a Healthy Diet, published November 4, 2022, https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/fiber/art-20043983, Accessed January 20, 2023.

This article is informational/educational only. It is not intended as medical guidance and is not intended as a substitute for professional medical advice or consultations with healthcare professionals. You should always consult with your doctor about significant changes in diet.