What if I told you that one thing could help you lose weight, improve your gut hormones and gut health, resolve bloating, regulate bowel movements, and balance hormones? It is so simple to add into your life that some of my patients think it’s too good to be true. We can do all of this and more by simply increasing our fiber intake. In my opinion, this small change is the most underrated aspect of nutrition. You may be thinking ‘well I eat fiber every day Dr. Sarah’, and I’m sure you do. My follow-up question would be how much. As a society we’re lucky if we consume an average of 15g of fiber today. The goal? 40-50g of fiber. Hear me out and let me convince you that it’s worth the fiber investment when it comes to its effects on gut bacteria.
The gut loves soluble fiber
There are two types of fiber: insoluble and soluble. Insoluble fiber is found in foods such as vegetables and whole grains and work by adding bulk to our stool to help speed up bowel movements. Soluble fibers are found in foods such as inulin, acacia, potato starch, beans, nuts, seeds, and psyllium. It works by attracting water to dissolve the fiber, which slows the transit time of food in our intestines.
Our gut particularly loves soluble fibres or resistance starches, which are the preferred fuel for many beneficial gut bacterial species. As a general rule, when your bacteria eat fibre, they produce short-chain fatty acids, which serve as fuel to the cells of the gut lining, known as enterocytes. These enterocytes protect the integrity of the lining, preventing leaky gut, inflammation, and food intolerances. Fiber also balances out the types of bacteria in your gut, which can help you lose weight, decrease inflammation, and protect against many diseases.
Sources of fiber
- Fruits and vegetables
My favourite part of a whole foods plant-based diet is the amount of fiber you inherently get from the fruits and vegetables you consume. It’s no wonder that vegans and vegetarians consume more fiber than omnivores! Luckily you’ll find both soluble and insoluble fibers in fruits and vegetables so you can reap all the benefits.
On top of being a source of fuel for our gut, it can also increase the anti-inflammatory bacteria, decrease the amount of inflammation and decrease insulin resistance.
Acacia is a great starting point if you have a sensitive gut. It is a more gentle prebiotic that can normally be purchased as a powder at most health food stores. It can help increase diversity of beneficial bacteria and it can help you lose body fat without the bloating and gas that may come with some other bacterial fuels.
- Resistance starch (potato starch)
Although not specifically a fiber, resistant starch can decrease insulin and insulin resistance.
How to introduce fiber
Have you ever tried introducing more fiber into your diet only to feel bloated and gassy? You’re not alone! Instead of giving up on fiber altogether, I want to help you introduce it properly. First, when you are adding more fuel to your bacteria’s fire, especially when they are not accustomed to it, they get excited! This can show up as transient gas, bloating, and some poop changes for three to five days. This should all be transient though. When it is not, or when the symptoms are severe, with diarrhea, pain, brain fog, low mood, or an increase in the inflammation in your body, then you should be digging deeper. A note of caution: if you are having prolonged or significant symptoms, please don’t tough it out. Listen to your body and stop. You may have found your underlying issue (an overgrowth or infection).
I hope after reading this you’re jumping on the fiber wagon with me. Something honestly so simple has such profound health benefits. In my new book, Finally Lose It, I go into detail of how fiber affects gut hormones as well. The list of benefits can go on and on. My meal plan in Finally Lose It is also the perfect stepping stone for increasing your fiber intake.
What are you favourite ways to make sure you’re reaching your fiber goals? I’d love to hear them!