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#007 The Core Four: Food

core four fiber food

Fiber doesn’t get enough love.

I feel like it’s the ‘stretching’ of the food world. You know, how workouts focus on cardio and strength with rarely a mention of stretching for injury prevention and mobility.

Similarly, fiber isn’t even included in macros. Yet, it has a profound effect on our health and longevity.

We’re still in the infancy of understanding the role of fiber (or nutrition for that matter) but new studies are beginning to highlight its importance and unique role.


This really surprised me.

I had no idea that different types of fiber have different effects on the gut microbiome. For years, the emphasis has been on fiber as a laxative but we’re starting to understand that its role is vastly greater.

Scientist have categorized fiber into 4 main types based on its physiochemical properties:

  • Soluble, viscous/gel forming, readily fermented fibers (like oats, barley and shiitake mushrooms)- they hit all 3 physiochemical properties; solubility, viscosity and fermentability. Fibers that are soluble, viscous, and fermentable have been shown to improve glycemic control and to lower blood cholesterol concentration with no laxative effect.
  • Soluble, viscous/gel forming, nonfermented fibers (chia seeds and psyllium)-improve glycemic control such as insulin regulation and lower cholesterol with a normalizing/adaptogenic effect on elimination. Meaning if constipated it can help you go, if you have loose stools it can firm them up.
  • Soluble, nonviscous, readily fermented fibers (fruits and veggies) these can have a prebiotic effect by feeding the gut bacteria and expanding population and diversity of bacteria. They have a mild laxative effect.
  • Insoluble, poorly fermented fibers (wheat bran)- these have a laxative effect but do not feed the microbiota. 


Functional fiber.

We want a rich and diverse population of microbes for optimal health. By increasing your fiber intake, we increase the diversity, efficiency and expand the population of microbes in our gut.

All good things!

Think of fiber as the primary food source for your microbiota. We’re not only feeding ourselves for optimal health, we’re also feeding a village of microbes.


Unfortunately, we're going in the wrong direction.

Most people hear Paleo Diet and think protein. The reality is our ancestors ate nearly 100g of fiber a day.

Currently, people living in non-non-industrialized nations average 50g of fiber a day.

Yet, the average American consumes roughly 12g of fiber a day which scientist believe may be driving up the number of metabolic and inflammatory diseases such as cardiovascular disease, type 2 diabetes, and obesity. It doesn’t end there.

We are just beginning to understand the extent that a healthy gut microbiome plays in our overall wellbeing. Recent studies indicate that risk of poor gut microbiome may also be influencing conditions such as mood and neurological disorders.


Reductionism is for the lab, not the table. 

You don’t need to go down the rabbit hole on this.

The different categories of fiber are interesting but should not be used as a food guide. We get in trouble when start trying to eat in a ‘reductionistic’ manner because that’s not how our bodies work.

Food is beautifully complex. Just including a mix of different foods like whole grains, beans, fruits and veggies throughout the day will cover all your bases. Don’t over think it!


Take a holistic approach.

Food is more than macros and we have enough to stress about. Keep it simple.

Michael Pollan said it best, “Eat ‘whole’ foods. Not too much. Mostly plants.”

  • Aim for 10g of fiber and 30g of protein per meal (= 30g fiber and 90g protein/per day)
  • Vary fiber types by simply eating a variety of foods
  • Easy ways to boost meals:
    • Add beans to soups, salads and grain bowls
    • Add chia seeds (8g of fiber per serving!), great in oatmeal, yogurt and smoothies
    • Add an avocado for 10g of fiber to literally anything 🙂

Would love to hear your thoughts on fiber. Is it part of your meal planning like protein? Thanks for your time. Have a great week!


With love and gratitude,



References: Dietary Fibre Modulates the Gut Microbiota