Nutrition 101 – All About Fiber
What is it?
Fiber comes exclusively from plants; it is what gives them their structure (just like bones & muscles give animals their structure!). Dietary fiber is the parts of the plants we eat which is resistent to our digestive process.
There are two categories for fiber: soluble and insoluble. Soluble dissolves in water; it absorbs it and becomes gel-like as it moves through your digestive system. Insoluble does not dissolve in water; it stays the same as it move through your digestive system.
Why is it important?
Most studies don’t differentiate between soluble and insoluble fiber, but in general they are both beneficial for our health and we need both of them in our diet! They help keep our gut bacteria happy, make sure we are having healthy bowel movements, and even help regulate our blood sugar levels.
Soluble fiber has been shown to decrease blood cholesterol levels and help regulate our blood glucose levels. A type of soluble fiber, inulin, has been shown to help decrease intestinal permeability (leaky gut) and regulate our immune system. Insoluble fiber helps increase our the bulk of our stool; it’s incredibly important for having healthy bowel movements and avoiding constipation. A diet rich in insoluble fiber has been shown to decrease the risk of certain cancers and decrease markers of inflammation. There is evidence it can improve insulin sensitivity, and is essential for regulating our hunger hormones.
How does it relate to stress?
Fiber is an important aspect for making sure our elimination pathways are functioning properly, so ensuring all the excess hormones or toxins that have been created by the body’s natural proceses or ingested are disposed of. Without sufficient fiber in our diet, we might not be having proper bowel movements and therefore increasing the burden on our body’s natural detoxification systems as these compounds are reabsorbed in our digestive tract.
During periods of chronic stress it’s possible you might experience some constipation; adequate fiber can help regulate your bowel movements. As you work to recover from the effects of this stress, your liver may need to detox more than before, making it even more crucial that you have a healthy digestive system support by adequate fiber.
How much do I need?
The majority of the population is not getting enough fiber in their diets. According to the British Nutrition Foundation, women in the UK are averaging just 17.2g per day and men only 20.1g. The recommended average intake is 30g!
However, when studied, it’s been seen that with high fiber diets the risk of cardiovascular disease, coronary events, stroke, colorectal cancer, and type 2 diabetes is decreasing. Currently there has been no upper limit set for fiber intake. If you are consuming a natural, whole foods diet, you should be able to easily get well beyond the 30g of fiber per day.
Where can I get it?
It’s better to get your fibre naturally in your diet from whole foods where it comes packaged with other vital nutrients our bodies need. You can find fiber in all plant foods, so vegetables and fruits, legumes, nuts and seeds, and grains.
I tend to recommend focusing on vegetables and fruit for your fiber needs, even though often grains are advertised as the best sources. Veggies and fruit on average have a similar level of fiber content, but are generally packed with many more vitamins and nutrients than you will get from other sources. One of the most abundant sources of fiber is in lentils / legumes, but the calories consumed in a serving of these means that vegetables still come out on top as the most nutrient dense.
This is why I always promote smoothies over juices – if you are juicing your fruit or vegetables you are taking out all the much needed fiber!
If you are thinking about taking a fiber supplement, I would first encourage you to look at your diet for where you can further improve to get natural, whole sources of fiber. And of course, always consult with a health professional before starting any supplementation.
Some fiber content examples:
- Black beans (1 cup): 15g of fiber, 227 calories
- Collard greens (1 cup): 7.6g of fiber, 63 calories
- Broccoli (1 cup): 5.2g of fiber, 55 calories
- Raspberries (1 cup): 8g of fiber, 64 calories
- Wheat (1 cup): 8.2g of fiber, 151 calories
Any lingering questions on fiber? Ask away in the comments below!
Ballantyne, S. (2013) The Paleo Approach. Las Vegas, USA: Victory Belt Publishing Inc.
British Nutrition Foundation (2019 February 28). Dietary Fiber. Retrieved from https://www.nutrition.org.uk/nutritionscience/nutrients-food-and-ingredients/dietary-fibre.html
Wilson, J.L. (2001) Adrenal Fatigue The 21st Century Stress Syndrome. Petaluma, USA: Smart Publications
World’s Healthiest Foods (2019 February 28). Fiber. Retrieved from http://www.whfoods.com/genpage.php?tname=nutrient&dbid=59