What's not a good source of fiber?

November 13, 2025 •

4 min read

According to the Mayo Clinic, processed foods often lose much of their dietary fiber during production. This means that while many products may appear as food, they are what's not a good source of fiber and can contribute to a diet lacking this essential nutrient.

Quick Summary

Processed foods, refined grains, and animal products are typically poor sources of fiber. They lack the necessary bulk for digestive health and can be high in sugar, fat, or sodium, offering limited nutritional value.

Key Points

Refined Grains Lack Fiber: The process of refining grains removes the fiber-rich bran and germ, turning them into poor fiber sources like white bread and white rice.
Animal Products Contain No Fiber: Meat, poultry, fish, eggs, and dairy are entirely devoid of dietary fiber, as fiber is only found in plant-based foods.
Processed Foods are Stripped of Nutrients: Many processed items, including certain snacks, desserts, and juices, lose significant amounts of fiber during production.
Added Fiber Isn't a Full Substitute: Foods with synthetic added fiber often lack the other vital nutrients found in whole foods and can be high in sugar.
Prioritize Whole Plant Foods: The best sources of fiber are unprocessed plant foods like fruits, vegetables, whole grains, nuts, and legumes.

Understanding Dietary Fiber

Dietary fiber is an essential carbohydrate found in plant-based foods that the body cannot digest. It plays a crucial role in maintaining a healthy digestive system, regulating blood sugar levels, and promoting satiety. However, not all food provides this benefit. Many common dietary staples and processed items are notably lacking in fiber content, despite sometimes having other nutritional components.

The Impact of Processing and Refining

Refined and processed foods are among the worst culprits when it comes to fiber deficiency. The refining process, particularly with grains, involves stripping away the outer layer, known as the bran, and the germ. These are the parts of the grain that contain most of the fiber and other vital nutrients. While some nutrients like iron and B vitamins may be added back in enrichment, the lost fiber is typically not replaced. This results in products that are high in starchy carbohydrates but low in the fiber needed for proper digestion.

Common examples of refined foods that are not good sources of fiber:

White bread: A single slice can contain less than one gram of fiber.
White rice: Unlike brown rice, the milling process removes the bran layer.
Refined pasta: Similar to white bread, most of the fiber is removed from traditional pasta.
Most pastries and cakes: Products made with white flour offer minimal fiber.
Fruit juices: Removing the pulp and skin from fruit drastically reduces the fiber content, leaving mostly sugar.
Soda and sugary drinks: These contain virtually no fiber.

Animal Products and Fiber

Fiber is exclusively found in plant-based foods. This means that animal products, such as meat, dairy, and eggs, contain no dietary fiber at all. While these foods can be part of a balanced diet and provide other essential nutrients like protein and fat, they should not be considered for fiber intake. This is an important distinction to remember when constructing meals to ensure a balanced nutritional profile. It's crucial to pair animal products with plant-based, high-fiber side dishes.

Animal-based foods that are not sources of fiber include:

Meat: Beef, chicken, fish, and pork.
Dairy products: Milk, cheese, and yogurt (unless fortified).
Eggs: Provide protein and vitamins, but no fiber.

The Problem with Fiber-fortified Foods

Some food manufacturers add synthetic or isolated fibers, known as "added fiber," to processed products like certain yogurts, cereals, and even drinks. While these products may legally be labeled as a "good source of fiber," relying solely on them to meet your daily needs is not ideal. Naturally occurring fiber in whole foods comes with a complete package of vitamins, minerals, and antioxidants that isolated fibers lack. Moreover, these fortified products often still contain high amounts of sugar and low overall nutritional density. For instance, a breakfast cereal marketed as high in fiber may still have a significant amount of added sugar.

Comparison of Fiber Sources

To highlight the difference between good and poor fiber sources, consider the following table:


Food Category	Good Sources of Fiber	Not a Good Source of Fiber
Grains	Whole-wheat bread, oats, brown rice, barley	White bread, white rice, refined pasta, most pastries
Fruits	Berries, apples with skin, pears, avocados	Fruit juices without pulp, canned fruit in syrup
Vegetables	Broccoli, green beans, carrots, potatoes with skin	Most vegetable juices, peeled potatoes, canned vegetables
Legumes & Nuts	Beans, lentils, chickpeas, almonds, chia seeds	Creamy peanut butter (low fiber), processed nut butters
Animal Products	Not applicable	Meat, fish, eggs, dairy

The Takeaway on Healthy Fiber Intake

To ensure you're getting sufficient, healthy dietary fiber, prioritize eating a variety of whole, unprocessed plant foods. This includes plenty of fruits, vegetables, legumes, nuts, and whole grains. For example, swapping white rice for brown rice or adding beans to soups can significantly boost your fiber intake. Furthermore, choosing whole fruits over juice and opting for whole-grain versions of breads and pastas is key. Relying on processed and refined foods, even those with added fiber, means missing out on a host of other beneficial nutrients that come packaged with natural fiber.

For more information on balanced nutrition, the Harvard T.H. Chan School of Public Health offers excellent resources on fiber and general dietary guidelines.

Conclusion

In summary, what is not a good source of fiber includes refined grains, most processed foods, and all animal products. While these items may be a regular part of a person's diet, they should not be counted on to provide the necessary fiber. Focus on increasing your intake of whole plant-based foods, which are the most reliable and nutrient-dense sources of dietary fiber. By making conscious choices, you can improve your digestive health, manage weight, and support overall well-being.

Frequently Asked Questions

You should generally avoid refined grain products like white bread and pasta, fruit juices without pulp, sugary drinks, most pastries, and any food derived from animals, such as meat, dairy, and eggs, when seeking to increase your fiber intake.

Refined grains are low in fiber because the milling process removes the outer layer (bran) and the germ of the grain, which are where the majority of the fiber is stored.

No, dairy products such as milk, cheese, and yogurt (if not fortified) do not contain any dietary fiber because it is a nutrient found exclusively in plant-based foods.

No, while fortified foods contain some fiber, they lack the complete package of vitamins, minerals, and other nutrients found in natural, whole food fiber sources. They may also be high in sugar.

It is better to eat whole fruit, including the skin and pulp, as these parts contain the most fiber. Fruit juice, with the pulp removed, provides far less fiber and mostly just sugar.

While some ultra-processed foods may have added fiber, many are high in saturated fat, salt, or sugar and should not be relied upon as a primary fiber source. It is healthier to choose whole, less-processed foods.

The best way is to focus on incorporating whole foods into your diet, such as switching to whole-grain bread and pasta, eating whole fruits and vegetables with skins, and adding legumes like beans and lentils to your meals.