Your Ultimate Fiber Guide
Warning: If you have IBS, Crohn’s, Celiac or any other inflammatory or chronic digestive diseases, refer to your physician or dietitian for all fiber recommendations. If you have an eating disorder, refer to your dietitian, physician and care team for questions as well.
What is fiber?
Fiber is a carbohydrate. There are many different forms of carbohydrates. Carbohydrates are our body’s main source of energy (glucose), meaning as we metabolize our food, it is carbohydrates which can be broken down to glucose the fastest. We need glucose to survive. Fiber is a special type of carbohydrate which is, in fact, indigestible, meaning the digestive system of the human body cannot breakdown and absorb fiber as a source of energy.
Something to note: when you think of fiber, think of maintaining hydration!
Why should I eat fiber then, if my body can’t use it for fuel?
Great question! The answer is that fiber is essential for our gut health. Our gut comprises of our stomach, small intestine and large intestine. Gut health is a vast subject, which is scientifically developing as we speak. Fiber is a critical component for the health of our entire digestive system.
When thinking of our stomach, fiber helps support our feeling of fullness (not the only aspect, but part of it). Eating a meal rich in fiber containing foods adds physical bulk to our meal. This helps our body in registering that feeling of fullness.
When considering our small intestine, fiber can assist in controlling our body’s absorption of glucose (as usual, these points are multifaceted depending on the individual scenario). We need glucose to survive, but having an even release of glucose is important for our body’s ability to maintain controlled blood sugar throughout the lifespan.
Moving on to our large intestine, fiber plays a role in the bulking of our stool and our body’s ability to move stool through our large intestine. In general terms, fiber helps us have solid poop and keeps our bowel movements regular! Yay!
Particular forms of fiber, called fermentable fibers, also help feed the helpful bacteria which live in our digestive system. We have bacteria all over our bodies! Some bacteria are harmful, but most of them are helpful and aid in maintaining a healthy “ecosystem”. Fiber helps feed this “ecosystem” and increase the number of healthy bacteria.
Okay interesting...so where can I find fiber in my diet then?
Fiber is only found in plant foods. Typical plant foods are fruits, vegetables, whole grains, nuts and seeds. In general, plant foods are our most nutritionally dense foods, meaning they contain the most vitamins and minerals per serving that our bodies need to function. Don’t be fooled though! All foods can fit in a healthy diet! Sitting around and only eating fruits and vegetables is not the goal.
As adults we should aim to consume 5 servings of fruits and vegetables combined per day. The recommended fiber amounts are:
Women - 25-28 grams per day
Men - 28 grams per day
Children
1-3 yrs old: 19 grams
4-8 yrs old: 25 grams
9-13 yrs old: 26 (F) 31 (M)
Alright great! Is there anything else about fiber I should know?
Yes! There are two kinds of fiber:
Soluble
Insoluble
Soluble fiber essentially means fiber which can dissolve in water. This would include foods like oatmeal, apples, chia seeds, flaxseeds, beans, sweet potatoes, lentils etc. This form of fiber helps our stool move easily through our digestive system.
Insoluble fiber is fiber which cannot readily dissolve in water. This would include foods such as kale, spinach, wheat products, brown rice, quinoa etc. This form of fiber assists in bulking of our stool, giving it shape and form.
*many foods contain both types of fiber - do not obsess over this, but keep a loose eye on the balance.
Lastly, water!! Fiber does not assist us much without healthy hydration, aka drinking our recommended amount of water (usually ~2L for adults). Without water, fiber can cause constipation, gas and bloating. It can be easy to imaging that bulking stool without water, doesn’t lead to the best results.
Okay so what are my main take-aways?
Aim to meet your 5-a-day goal of fruits and vegetables (90% of Americans do not - uh oh!)
Aim to make at-least 1/2 of your daily grains whole grains (what are whole grains?)
Aim to meet your daily hydration goals (getting a 1 liter clear bottle is recommended)
Consider your fiber sources and make sure you are getting adequate amounts of both types!
