The Fiber Gap: Why Most Americans Fall Short — and Why It Matters

While protein continues to dominate the wellness conversation, there is another essential macronutrient that consistently goes unnoticed: fiber. Despite its well-documented health benefits, only about 5% of adults meet the daily recommendations. This widespread shortage has prompted the 2010 Dietary Guidelines for Americans to classify fiber as a “nutrient of concern,” highlighting what researchers often call the “fiber gap.”

Fiber is found exclusively in plant-based foods (e.g., legumes, oats, vegetables, fruits and seeds). It exists in several forms, each of which plays a critical role in maintaining various aspects of health. Regardless of an individual’s dietary pattern, fiber should not be overlooked or minimized. Its contributions to regularity, satiety and digestive comfort make it essential to daily wellness.*

Let’s explore why fiber is frequently under-consumed, what this means for overall health and how individuals can begin to close this critical nutritional gap.

Understanding the Fiber Gap: Recommendations and Challenges

Unlike other macronutrients, fiber passes through the digestive system largely intact. It provides zero calories but offers substantial physiological benefits. According to the 2015–2020 Dietary Guidelines for Americans, women ages 19-50 should aim for 28 grams of fiber daily, while men in the same age range require 38 grams. These targets shift slightly with age, but the need remains significant across the lifespan.

Many people shy away from fiber due to its association with digestive regularity, a topic that can feel taboo. However, maintaining healthy elimination patterns is foundational to well-being. 

Fiber-rich foods also tend to be carbohydrate sources. That’s because fiber is technically a carbohydrate that resists digestion. As it moves through the gastrointestinal tract, it confers various benefits, from supporting metabolic health to nurturing the gut microbiome.

Whole food-based eating patterns like the Mediterranean diet or plant-forward diets naturally provide abundant fiber. However, these diets also require time and preparation. As a result, even the most health-conscious individuals may find it difficult to meet their fiber needs consistently.

Why Fiber Is a Nutrient of Concern

The body of research around fiber continues to grow, but several core benefits are well established. Fiber supports:

• Digestive health and regularity: By promoting efficient elimination, fiber contributes to overall gastrointestinal comfort and health.*
• Satiety and appetite regulation: Dietary fiber can promote feelings of fullness, support mindful eating and weight management when combined with balanced nutrition and lifestyle choices.*
• Balanced glycemic response: Soluble fiber, in particular, slows digestion and supports healthy post-meal blood sugar responses.*
• Cardiovascular health: Certain fibers help maintain healthy cholesterol levels already within normal ranges.*
• Gut microbiome diversity: Fermentable fibers act as prebiotics, nourishing beneficial bacteria and contributing to microbiome balance.*

Types of Fiber

Understanding the different types of fiber and how each functions can help tailor recommendations for clients based on individual needs.

Soluble Fiber

Soluble fiber dissolves in water, forming a gel-like substance that slows digestion and assists in nutrient absorption. It is associated with heart health and metabolic balance.

• Sources: Psyllium husk, oats, legumes (lentils and beans), green vegetables, and various fruits.

Insoluble Fiber

Often referred to as “roughage,” insoluble fiber adds bulk to the stool and facilitates more efficient transit through the digestive system.

• Sources: Whole grains, wheat bran, nuts, seeds, and vegetables like leafy greens.

Fermentable Fiber

Fermentable fibers are broken down (fermented) by gut bacteria and serve as prebiotics, which support a healthy gut ecosystem.

• Sources: Solnul® resistant starch, chicory root, green bananas, cooked and cooled rice or pasta, onions, garlic, and fiber-specific supplements.

Bridging the Gap: Practical Guidance

Health professionals can play a key role in helping clients and patients recognize the value of fiber and implement strategies to increase intake. Here are a few evidence-informed recommendations:

• Encourage whole food diversity: Prioritize a variety of fiber-rich plant foods to cover all types of fiber.
• Educate on fiber supplements: When whole food sources aren’t sufficient, supplemental fibers may be appropriate and effective.
• Support gradual change: Advise increasing fiber intake slowly and alongside adequate hydration to minimize gastrointestinal discomfort.

Get a Boost with Let’s Go Fiber+ 

Enzymedica’s new digestive health supplement, Let’s Go Fiber+, is launching soon. This fiber drink mix includes prebiotics, probiotics and postbiotics for daily regularity and gut health.* With 5 g of fiber per serving, it is a convenient format your clients can easily integrate into their everyday routine. 

It includes a fermentable and upcycled resistant starch, sustainable acacia fiber, 1 billion CFUs of probiotics (Bacillus coagulans) and the clinically studied postbiotic Bifidobacterium longum HT-ES1, to support the microbiome.* Most insoluble fiber is not fermentable, while most soluble fiber is fermentable. The fiber in Let’s Go Fiber+, Solnul®, is both insoluble and fermentable. It is also FODMAP-friendly and Certified Upcycled.