top of page

Fiber 101

Fiber is a class of carbohydrates that are unable to be broken down and digested by human enzymes, so it passes through the gastrointestinal tract relatively untouched until it reaches our gut microbes.  Fiber has a whole host of health benefits, but it’s important to note that not all fiber is the same.  We have many different ways to classify fiber, the most common being soluble and insoluble.


Soluble fiber absorbs water and slows movement of food through our digestive tract.  Soluble fiber is also important in that it can help lower cholesterol and aid in preventing spikes in blood glucose.  Also, most of the fiber that can be broken down by our gut microbiota are soluble in nature, so having enough soluble fiber ensures that you’re “feeding” those good bacteria in the gut.  Good sources of soluble fiber include beans, peas, oatmeal, berries, and brussels sprouts. 


On the other hand, insoluble fiber does not absorb water and instead adds bulk to our stools and speeds up the movement of food through our digestive tract.  You can think of insoluble fiber as a broom that sweeps out our gut.  Like soluble fiber, insoluble fiber can help with regularity and feelings of satiety.  Some common sources of insoluble fiber include whole grain products, brown rice, and most fruits and vegetables with edible skin.


Having a balance of soluble and insoluble fiber in your diet is incredibly important.  Too much soluble fiber might lead to constipation and too much insoluble fiber might have you running to the bathroom every few hours. 


So how much fiber do you need? Current recommendations for dietary fiber are 25g per day for females and 38g per day for males.  However, a more precise method of assessing fiber intake is using fiber density.  This is looking at the amount of fiber in the diet per calories consumed.  When looking at fiber density, the typical recommendation is to aim for 14g of fiber per 1000 calories.  So, someone eating around 2500 calories per day should be aiming for around 35g of fiber.


If you’re eating too little fiber, it’s important to slowly increase your intake over time instead of diving right into those higher recommendations.  Most people can tolerate a 2-5 gram/week increase in fiber, but responses are highly individualized.  Test out what’s right for you while also keeping tabs on your stool consistency and frequency. 


Repeat after me, more is not always better! You can definitely eat too much fiber.  Fiber adds bulk to food with little caloric value.  If you are eating so much fiber that it is displacing more nutrient/energy dense foods and leading you to undereat calorically, that can be an issue.  Additionally, too high of fiber intake may interfere with absorption of certain nutrients, leading to vitamin and mineral deficiencies.  


Finding your sweet spot with fiber might take a little trial and error but your gut and cardiovascular system will thank you!


Until next time,

Jessie


Resources:

Comentários


bottom of page