What are not good sources of fiber?

December 25, 2025 •

4 min read

According to the Academy of Nutrition and Dietetics, most Americans get only about 15 grams of fiber per day, far short of the recommended 25-38 grams. When trying to increase intake, it is important to know what are not good sources of fiber to avoid falling short of your health goals.

Quick Summary

This article explores the foods that are poor sources of dietary fiber, such as refined grains, fruit juices, and many processed snacks. It explains why these options lack beneficial fiber and offers healthier, whole-food alternatives for improved digestive health.

Key Points

Refined Grains Lack Fiber: During processing, the fiber-rich bran and germ are removed from grains, making white bread, pasta, and rice poor sources.
Fruit Juice is a Poor Source: Juicing removes the skin and pulp of fruit, which contain most of the fiber, leaving behind concentrated sugar.
Animal Products Have Zero Fiber: Meat, poultry, fish, eggs, and dairy products do not contain dietary fiber because fiber only comes from plants.
Processed Snacks are Deceptive: Many snack foods and sweets are low in fiber, and those fortified with added fiber often lack the full nutritional profile of whole foods.
Prioritize Whole Foods: The best sources of fiber are whole grains, fruits, vegetables, legumes, nuts, and seeds in their natural, unprocessed state.
Avoid Refined Sugars: The combination of low fiber and high sugar in processed foods and juices can lead to blood sugar spikes and poor digestive health.

The Processing Problem: Why Refined Grains Fall Short

When it comes to fiber, all grains are not created equal. The primary difference lies in the processing. Whole grains contain the entire grain kernel—the bran, germ, and endosperm. The bran and germ are rich in fiber and other nutrients. However, refined grains undergo a milling process that strips away these components, leaving only the starchy endosperm.

Examples of refined grains that are not good sources of fiber include:

White bread and pasta: Unlike their whole-grain counterparts, these products contain little to no dietary fiber.
White rice: Brown rice is a whole grain, but white rice is a refined grain with most of its fiber removed during processing.
Refined cereals: Many breakfast cereals are made from refined flours and contain minimal fiber unless it has been added back.

Some refined grains are 'enriched,' which means some B vitamins and iron are added back after processing. However, the fiber is typically not returned. For this reason, always choose whole grains over refined grains to ensure a higher fiber intake.

Fruit Juice vs. Whole Fruit: A Case of Missing Fiber

While fruit is generally an excellent source of fiber, fruit juice is a poor substitute. The juicing process removes the skin and pulp, where most of the fiber is concentrated. This transforms a nutritious whole food into a concentrated source of sugar with minimal fiber.

Rapid Sugar Absorption: Without fiber to slow down digestion, the sugars in juice are absorbed quickly into the bloodstream, causing a spike in blood sugar levels.
Lack of Satiety: The absence of fiber also means juice is far less filling than whole fruit, which can lead to overconsumption of calories.

In contrast, eating a whole fruit provides both the soluble and insoluble fiber, which contributes to better blood sugar control and a feeling of fullness. For example, an orange provides significant fiber, whereas a glass of orange juice offers almost none.

The Low-Fiber Reality of Animal and Dairy Products

Dietary fiber is an indigestible part of plants. Therefore, by their nature, animal products contain zero dietary fiber. This includes all types of meat, fish, poultry, eggs, and dairy products like milk, cheese, and yogurt. While these foods are essential sources of protein and other nutrients, they should never be considered a source of fiber. A balanced diet requires incorporating plant-based foods to meet your daily fiber goals.

The Deception of Processed Snacks and Sweets

Many processed snacks and sweets are low in fiber, often because they are made with refined flours and added sugars. Even products that advertise themselves as containing fiber often use added, isolated fibers that do not offer the same comprehensive nutritional benefits as fiber from whole foods.

Here's a breakdown of common processed foods that are not good fiber sources:

Sweets and Baked Goods: Cookies, cakes, and other pastries made with white flour and sugar provide almost no beneficial fiber.
Salty Snacks: Pretzels, potato chips, and crackers are typically made from refined grains and are devoid of meaningful fiber content.
Frozen Meals and Convenience Foods: Many ready meals and highly processed items are designed for convenience, not nutrition, and are often very low in fiber.

Comparison of Fiber Sources: Whole vs. Refined and Processed


Feature	Whole Foods (Good Fiber Sources)	Refined/Processed Foods (Poor Fiber Sources)
Composition	Contains the entire plant part, including bran and pulp.	Bran and germ are removed, leaving mainly starch.
Fiber Content	Naturally high in both soluble and insoluble fiber.	Very low or zero fiber; some may have isolated fiber added.
Sugar Impact	Fiber slows sugar absorption, preventing spikes.	High sugar content, especially in juices, causes rapid blood sugar spikes.
Satiety	The bulk from fiber helps you feel full longer.	Lacks fiber, leading to less satiety and potential overeating.
Nutrients	Rich in vitamins, minerals, and antioxidants.	Many nutrients are stripped away during processing.

Conclusion: Prioritize Whole, Plant-Based Foods

When aiming to increase your dietary fiber intake, the clear strategy is to focus on whole, unprocessed, plant-based foods. This includes whole grains, fresh fruits and vegetables with their skins, legumes, nuts, and seeds. Conversely, you should view refined grains, fruit juices, most processed snacks, and all animal products as poor or non-existent sources of fiber. By being mindful of these distinctions, you can make informed choices that significantly contribute to your overall digestive health and nutritional well-being. Focus on incorporating a wide variety of plant foods into your diet rather than relying on fortified products or supplements, which often lack the full spectrum of benefits found in nature. For a deeper dive into improving your diet, the Harvard T.H. Chan School of Public Health offers valuable insights on healthy eating.

Frequently Asked Questions

White bread is made from refined grains that have had the bran and germ, the fiber-rich parts, removed during the milling process. This stripping of the outer layers results in a product with very little dietary fiber.

No, fruit juice is not as good as whole fruit for fiber. The juicing process removes the pulp and skin, where most of the fiber is found. This results in a sugary liquid with very little fiber, which can cause blood sugar spikes.

No, meat and dairy products do not contain dietary fiber. Fiber is only found in plant-based foods, so all animal products, including meat, fish, eggs, and dairy, are naturally fiber-free.

Fiber supplements and fortified foods often contain isolated fibers that do not provide the full range of vitamins, minerals, and other nutrients found in whole, natural food sources. It is generally healthier to get fiber from a diverse diet of plant-based foods.

Yes. Many highly processed foods that are advertised as high-fiber, such as certain cereals or snacks, can also be high in added sugars, unhealthy fats, and sodium. The best sources of fiber are whole foods.

To increase fiber, swap white bread for whole-grain bread, white rice for brown rice, and eat whole fruits instead of drinking juice. Incorporate more vegetables, legumes like beans and lentils, and nuts and seeds into your diet.

The fiber in whole foods, both soluble and insoluble, works to add bulk to your stool and help regulate bowel movements. This contributes to better digestive health and a healthier gut microbiome, which is not fully replicated by most processed or fiber-fortified options.