5 Reasons Why Fiber is the New Protein

Within the popular discourse on nutrition, protein has long been heralded as the keystone nutrient of a healthy diet due to its purported roles in muscle building and weight management. To be sure, adequate protein is absolutely essential. It’s also true, however, that the majority of Americans consume far more of it than is necessary or beneficial. 

So, what’s really missing from the American diet? I can think of a nutrient that virtually everyone is lacking, one that's often overlooked but holds immense potential for our health: fiber. 

What even is fiber? Simply put, it’s the indigestible forms of carbohydrates found in plants. From grade school biology, you’ll recall that cellulose fibers are what helps plant cells maintain their rigid structure. That’s just one example, but there’s a wide array of fibers in the plant-based foods we eat. 

How exactly does this plant roughage benefit you? Glad you asked. Here are five compelling health reasons that will have you believing fiber is the new protein.

1. Most People Are Actually Deficient in Fiber

I gave this one away in the intro, but it’s worse than you’re imagining. More than 95 percent of Americans (and, in all likelihood, you!) eat a diet deficient in fiber. Most adults don’t even come close to getting the 25- to 35-gram minimum we should be eating every day. 

But who can blame us? In a world inundated with high-protein marketing and fad diets, fiber is relegated to the sidelines. The bread and butter (no pun intended) of the omnipresent food industry are refined foods that, by definition, have most

fibers removed through processing. If we were all to put fiber center stage in our diets, it could pose a threat to the bottom lines of food manufacturers. Marketing around protein-rich foods has therefore been a convenient means of deflecting attention away from the fiber deficiency problem. 

OK, so if almost everyone’s diet is lacking in fiber, and we aren’t all immediately dropping dead from it, maybe it’s not that important … right? Wrong! Read on to see why.

2. Fiber Reduces Blood Cholesterol and Cardiovascular Risk

Cardiovascular disease remains a leading cause of death in the United States, but did you know that fiber offers protection against it? That’s because fiber helps lower cholesterol in the body through several key mechanisms. 

Soluble fibers, like those in oats, psyllium husk, and fruit, form a gel with the water in your digestive tract that is capable of trapping your body’s cholesterol-derived bile acids. By binding to these bile acids, fiber prevents them from being reabsorbed, which in turn prompts the liver to use the cholesterol in your blood to make new bile acids. This process lowers blood cholesterol levels, thereby reducing risk for developing atherosclerosis.

Insoluble fibers, like the aforementioned cellulose, add bulk to stool and promote regular bowel movements. The fiber binds cholesterol and other waste products, which are then more efficiently excreted. Once again, the overall effect is a reduction in cholesterol in the blood, in this case by inhibiting absorption from food.

But the cardiovascular benefits don’t stop there! High fiber diets have been shown to improve the elasticity of blood vessels and promote vasodilation through increased production of nitric oxide, all of which help lower blood pressure. Maintaining a healthy blood pressure, in turn, reduces risk for deadly and debilitating strokes and heart attacks.

3. Higher-Fiber Diets Are Linked to More Muscle Mass in Old Age

Adequate protein and weight training aren’t the only things you need to keep your muscles healthy and strong as you age. Here, too, fiber and fiber-rich foods play an important role.

See, contrary to popular belief, the benefits of fiber extend far beyond digestive health. High-fiber diets, especially those containing plenty of whole grains, can also help preserve muscle by mitigating insulin resistance. In particular, insoluble

cereal fiber has been shown to reduce risk for type II diabetes and improve insulin resistance—independent of weight loss. By protecting against this metabolic disease, dietary fiber may help protect against muscle wasting driven by insulin resistance.

You may have heard of the term “inflammaging,” used to describe how chronic inflammation hastens the aging process. This inflammation likely contributes to age-related muscle loss, a condition known as sarcopenia. Fiber metabolites, along with the antioxidants that come along with fiber-rich foods, have anti-inflammatory properties that help to calm the systemic inflammation that contributes to muscle loss. In fact, many studies have now demonstrated an association between fiber intake and more muscle mass in older adults.

Why is muscle wasting a big deal, anyway? Simply put, strong muscles support the mobility, balance, and overall functionality that keep us more active over a longer period of our lives. Falls can quickly become deadly for older adults, so

working more fiber-rich foods into our diets at any age—along with maintaining a resistance exercise regimen and an adequate protein intake—will pay dividends in our later years. 

4. Fiber Means More Plants, and Plants Mean Better Health

One of the hallmarks of a fiber-rich diet is its emphasis on plant-based foods.

Plants offer a treasure trove of essential vitamins and minerals, as well as beneficial phytochemicals and antioxidants, that are low in the standard American diet. 

Furthermore, plant foods boast impressive nutrient density without tipping the scale on calorie intake, making them an invaluable ally in the fight against cardiometabolic diseases like diabetes. Perhaps that’s why research consistently shows plant-rich diets are associated with greater longevity and healthspan along with lower risk for cancer, type II diabetes, and cardiovascular disease. 

Take this recently published systematic review and meta-analysis perfectly demonstrating this point. Harvard researcher Yeli Wang and colleagues reviewed 76 studies encompassing over two million participants and were able to distinguish plant-based diets from their conventional counterparts and even healthy plant-based diets from unhealthy plant-based diets.

What they found is that adherence to a healthy plant-based dietary pattern—more whole, fiber-rich plants and fewer refined products—saw significant drops in relative risks for cardiovascular diseases (15% lower), type II diabetes (21% lower), cancer (13% lower), and overall mortality (14% lower). This was also true of risk for stroke (11% lower) and colorectal cancer (15% lower). 

Importantly, unhealthy plant-based dietary patterns (more refined and processed) increased risk for some of these same diseases. All the more reason to focus your meals on fiber-rich whole foods!

5. Fiber Feeds Your Gut Microbiota

The trillions of microbes inhabiting our lower digestive tracts play a pivotal role in our health, and scientists continue to gain new insights every year into their importance. Beneficial strains of bacteria feed on the dietary fiber we eat but can’t digest, so consuming a variety of plants helps select for numerous strains of good bacteria and promotes a diverse and resilient gut ecosystem. 

What does this all mean for your health? A flourishing microbiome isn’t just about the gut itself. Consider that your gut microbiota enhance immunity by crowding out harmful bacteria and other pathogens while also synthesizing nutrients and other compounds that support good health. 

That brings us back to fiber. When gut bacteria break down fiber, they produce short-chain fatty acids, which have been shown to reduce inflammation, improve muscle metabolism, exhibit anti-cancer properties, decrease cholesterol synthesis in the liver, and might even impact mood and cognition. 

That’s why, by nurturing our gut bugs with fiber-rich foods, we can lay the foundation for long-term health and well-being.

Now, you may be thinking, Thanks for the info, but how do I start getting more fiber into my diet? The best thing you can do is work with a registered dietitian if you have specific health concerns, but here are some quick tips to get the ball rolling.

It starts by switching out the refined grains in your cupboard—white pasta, white rice, white bread—for their whole-grain counterparts. This alone will easily add another five to ten grams of fiber per day to your diet. Next, sneak in some beans: hummus, roasted chickpeas, lentils, baked beans, black bean burgers, tofu, white bean dip … the possibilities are endless. 

If you aren’t already getting your five servings per day or fruits and vegetables, start today. Fresh fruit is perfect any time of day—as part of a meal, as a snack, or even as a dessert. And if you think you don’t like vegetables, find new ways of preparing them; season them well so they’re bursting with flavor! Lastly, don’t forget about nuts and seeds. Those crunchy morsels are high in protein and healthy fats, too.

If you’ve made it this far, you’re already ahead of the curve: You know you need more fiber, you know why, and you know where to start getting more. Embracing fiber as an essential component of our diets will revolutionize our approach to nutrition. Instead of fixating on ‘macros’, we can focus on expanding the diversity of foods that nourish us as we learn to value all that plants have to offer. So move over, protein; let's make fiber the nutrient to champion!