How Important Is Fiber?

With the popularity of virtually anything that contains fiber these days, it’s hard to think of anything fiber doesn’t do. Take some secondhand interpretations of the research and throw in a little bit of anecdotal evidence and you’ve got something like this:

• Take fiber supplements for heart health
• Take fiber supplements for weight loss
• Take fiber supplements to live longer
• Eat fiber to improve your digestion
• Eat fiber for more energy

And so on.

Am I saying fiber is bad? Far from it. The problem, however, is that the original science looking at fiber rarely says the same thing as the secondhand interpretations do.

A research paper on fiber might find something like “people who had more fiber in their diet were 10% less likely to be overweight”. On the surface, that sounds pretty clear cut, although far less convincing than the “fiber automatically sheds pounds” you might get from a marketers interpretation. However, the main issue is that most of these studies fail to isolate fiber from other variables, and also fail to show that fiber actually causes these improvements.

In other words, if we actually looked at the research findings, our original list might look a bit more like this:

• Fresh vegetables, which have fiber in them, seem to improve heart heath
• People eating more fruits, vegetables and other whole foods are less likely to be overweight than people eating mostly processed food without fiber
• Heavily refined grains cause digestive issues, and don’t happen to have fiber in them
• People who eat nutrient-dense whole foods tend to have more energy

Compare that to the list above. Can you see why looking at the actually research findings as opposed to simplifying to the point of “fiber causes health” is important?

Again, I’m not saying that fiber isn’t good for us or that we don’t need it. It’s simply a small component of overall health, and it’s benefits are often overstated. As highlighted in the article What does Vitamin B12 Do, it’s important not to put too much emphasis on a single nutrient, as doing so often leads us to exclude other aspects of a healthy diet. An obvious example of this would be people who try to avoid animal products at all costs, and therefore end up with vitamin B12 deficiency.

Eating fiber is great. Get your fruits and vegetables. But don’t convince yourself that it’s the only important variable for health or weight loss.