Nutrient explainer · Gut Health

The fiber gap: why most of us fall short, and easy ways to close it

Protein gets all the attention these days. But there's another nutrient most Americans miss, by a lot: fiber. More than 90% of women and 97% of men don't get the amount recommended. Here's why fiber matters, how much you need, and how to add more without feeling bloated.

By the Herbal Bee teamUpdated 3 min read

A man in a bright kitchen after a workout, with a smoothie and a bowl of fruit

What fiber does

Fiber is the part of plant foods your body can't fully digest. That's exactly why it's useful. There are two main kinds:

  • Soluble fiber (in oats, beans, apples and psyllium) absorbs water and forms a gel. It helps you feel full, slows how fast sugar enters your blood, and helps lower cholesterol.
  • Insoluble fiber (in whole grains, nuts and vegetable skins) adds bulk and helps food move through your gut, which supports regularity [2].

Prebiotics are certain fibers, like inulin (found in chicory root, onions, garlic and bananas), that feed the helpful bacteria in your large intestine. When those bacteria ferment fiber, they make compounds that nourish the cells lining your gut. They also make gas, which is why adding fiber too quickly can leave you bloated [2].

Who tends to fall short

Almost everyone [1]. Fiber gaps are most common when your diet is built around:

  • Refined grains like white bread, white rice and regular pasta.
  • Processed snacks and fast food.
  • Few beans, vegetables, fruit, nuts or whole grains.

Some people also limit fiber on purpose because certain foods make them gassy. The answer there is usually going slower, not giving up.

What a fiber gap can lead to

Too little fiber can contribute to [2]:

  • Constipation, hard stools or straining.
  • Feeling hungry soon after meals.
  • Bigger swings in energy after meals.

Over time, eating patterns high in fiber are linked with better heart and gut health. If you have ongoing changes in your bowel habits, belly pain or blood in your stool, see your doctor rather than just adding fiber.

How much you need

Age Women (g/day) Men (g/day)
19–30 28 34
31–50 25 31
51+ 22 28

Source: Dietary Guidelines for Americans, 2020–2025, as summarized by NIDDK [1][2]. The Daily Value on labels is 28 g. There's no upper limit for fiber from food.

Top high-fiber foods

Food Serving Fiber (g) % Daily Value
High-fiber cereal, unsweetened ½ cup 14.0 50%
Navy beans, cooked ½ cup 9.6 34%
Artichoke, cooked 1 cup 9.6 34%
Lima beans, cooked 1 cup 9.2 33%
Guava 1 cup 8.9 32%
Green peas, cooked 1 cup 8.8 31%
Adzuki beans, cooked ½ cup 8.4 30%
Split peas, cooked ½ cup 8.2 29%
Breadfruit, cooked 1 cup 8.0 29%
Raspberries 1 cup 8.0 29%

Source: Dietary Guidelines for Americans, "Food sources of dietary fiber," based on USDA FoodData Central [3]. %DV calculated from the 28 g Daily Value.

Easy wins from around the world: black or pinto beans in tacos, dal or chana with rice, red bean (adzuki) desserts, split pea soup, guava or sapote as a snack, and oatmeal with raspberries.

Food first, then supplements

Add fiber slowly. Add one high-fiber food every few days, and drink extra water as you go [2]. Your gut bacteria need time to adjust.

A few simple swaps:

  • White bread → whole-grain bread
  • White rice → half brown rice, or rice with beans
  • Chips → popcorn or a handful of nuts
  • Juice → whole fruit

Fiber supplements: if you can't get enough from food, a fiber supplement may help.

  • Psyllium had the most consistent benefit for constipation in a 2025 review of trials [4].
  • Inulin and other prebiotics feed gut bacteria, but they're more likely to cause gas, and inulin blends didn't help constipation in that same review [4].
  • Take fiber supplements with plenty of water, and take other medicines at a different time, because fiber can slow how some are absorbed.

Where you'll find fiber in our products

These Herbal Bee formulas contain prebiotic fibers:

  • Gut Health: chicory root inulin and larch arabinogalactan, 50 mg each per serving
  • GLP-1 Advanced: chicory root inulin, 200 mg per serving

Capsules hold only a small amount, much less than the grams of fiber you'd get from a serving of beans. Food is still your main fiber source.

Related reads

Sources

  1. US Departments of Agriculture and Health and Human Services. Dietary Guidelines for Americans, 2020–2025. Dec 2020. https://www.dietaryguidelines.gov/sites/default/files/2020-12/Dietary_Guidelines_for_Americans_2020-2025.pdf
  2. NIDDK. "Eating, diet, & nutrition for constipation." https://www.niddk.nih.gov/health-information/digestive-diseases/constipation/eating-diet-nutrition
  3. DietaryGuidelines.gov. "Food sources of dietary fiber." https://www.dietaryguidelines.gov/resources/2020-2025-dietary-guidelines-online-materials/food-sources-select-nutrients/food-0
  4. British Dietetic Association. Dietary management of chronic constipation in adults: guidelines. J Hum Nutr Diet. 2025. doi:10.1111/jhn.70133. Summary: https://www.healthline.com/health-news/chronic-constipation-new-dietary-guidelines

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

This article is for general education and isn't medical advice.

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