Where’s the Fiber?

1. Lettuce 
2. Celery 
3. Lima beans 
4. Spinach 
5. Raspberries
   

Correct answer:

c) Lima beans

e) Raspberries

What you should know: 

Most of us have learned that food contains three types of macronutrients—that is, components of food that we should consume in relatively large amounts to stay healthy. These are of course carbohydrates, fats, and proteins. Sometimes water is included as a macronutrient, something else we consume in relatively large quantities that is necessary for survival. But most of us did not learn that there’s a fifth component of food, also necessary to health in relatively large quantities. That’s fiber.¹ 

The technical meaning of fiber depends on whether it’s coming from a botanist, a chemist, or a nutritionist, but a definition that is widely agreed on was published in 1985: “Dietary fibre consists of remnants of plant cells resistant to hydrolysis (digestion) by the alimentary enzymes of man.”² 

Basically, then, fiber is the parts of plants that we find difficult to digest. 

Why is it not widely accepted knowledge that fiber is a vital macronutrient? Possibly because it mostly can’t be digested, so it doesn’t provide nutrition to our cells. But current research tells us that diets higher in fiber reduce risk for chronic diseases such as cardiac disease, stroke, type 2 diabetes, and colon cancer, and in fact reduce the risk of death itself.³

We also know that most people aren’t consuming nearly enough fiber. Estimates are that primitive humans, who lived mostly on plants, consumed an average of around 100 grams of fiber a day. (For reference, one apple with the skin has around⁴ grams of fiber.) Modern adults in the U.S. get 10 to 15 grams per day, about half the amount recommended by the FDA. 

If you were getting less than half of the carbohydrates, fats, protein, and water that you need for health, the effects would be obvious, and the diagnosis would be malnutrition or starvation. Fiber doesn’t get the respect it should have for at least two reasons. First, the effects of fiber malnourishment aren’t immediately obvious and are not easily connected to their cause. Second, natural fiber is present in quality, real foods, much less so in processed foods, and definitely not in the ultra-processed foods that make up most of the U.S. food supply.⁴

So if you are charting a course to a healthier life, you’ll want to give natural fiber the respect it deserves, as one of the five most important things you can consume each day, whether it’s called a macronutrient or not. Lima bean and raspberry salad, anyone? 

References:

1. Macronutrients, USDA. nal.usda.gov/human-nutrition-and-food-safety/food-composition/macronutrients
2. Dietary fibre in foods: a review, Journal of Food Science Technology, 2012.
3. Association Between Dietary Fiber and Lower Risk of All-Cause Mortality: A Meta-Analysis of Cohort Studies, American Journal of Epidemiology, 2015.
4. See also the eSavvyHealth Real Food article, How to Spot Fake Fiber.