Oat Fiber vs Oat Flour or Oat Bran vs Oatmeal

If you are an oat lover, you have probably noticed there are many different oat products available. You may have seen oat fiber vs oat flour or oat bran vs oatmeal.  You may be wondering what’s the difference, and how are you supposed to use them all? 

This article goes over the differences between these four oat products and the best way to use each of them. 

Brief Overview

The four oat products that are compared in this post are oat fiber, oat flour, oat bran, and oatmeal. 

Oat fiber is made from the husk (outer shell) of an oat and is rich in insoluble fiber. It is used as an addition to baked goods or as a thickening agent.  

Oat flour is made from ground whole oats and can be used the same way as other flours are in baking. 

Oat bran is the outer layer of the whole oat and is high in protein and fiber. It can be used on its own to make a hot porridge, or as a topping for yogurt and smoothies.

Finally, oatmeal is made from whole oats. There are multiple types of oats, which will be looked at in greater detail later in the article. These are the oats that you are probably most familiar with and are often used on their own to make hot porridge, overnight oats, or in baking. 

Oat products are very versatile and can be easily incorporated into anyone’s daily eating habits. 

They are nutrient dense, offering fiber, protein, and vitamins and minerals such as B vitamins, zinc, iron, calcium, and potassium. 

They are also gluten free and keto friendly!

Health Benefits

Oats and oat products are a superfood. They offer a variety of health benefits including digestion, heart health, blood sugar regulation, weight management, and cancer prevention! 


Oat products are high in fiber, which helps promote healthy digestion and bowel movements, preventing constipation. 

Oat products include both soluble and insoluble fiber (except for oat fiber which is only insoluble fiber). 

Soluble fiber helps to absorb water in the digestive tract and slow the digestion process, which helps with nutrient absorption (1). Insoluble fiber is needed to build bulk for our stool (1).

Heart Health

Soluble fiber can help to lower LDL cholesterol (the bad cholesterol) which may reduce the risk of heart disease. 

Soluble fiber will bind cholesterol, causing it to be excreted in our stool rather than absorbed into the bloodstream (1).

This is important because a buildup of LDL cholesterol in the bloodstream can cause blockages in the arteries, which puts strain on the heart, putting you at a higher risk for heart disease. 

Blood Sugar

Fiber also helps to control blood sugar levels (2).

Blood sugar refers to the amount of glucose that is found in your blood. When we eat carbohydrates, our bodies break them down into glucose, which is then used for energy.

However, having too much glucose in your blood can be harmful and is a condition called hyperglycemia (or high blood sugar), often seen in those living with diabetes. 

Fiber is a type of carbohydrate that passes through our digestive tract without being broken down into glucose. Because of this, it does not raise blood sugar levels.

As mentioned before, fiber also helps to slow down digestion of sugar which can prevent spikes in blood sugar after eating.

Body Weight

Since fiber helps to slow down digestion, it helps to keep you feeling full for longer after eating, meaning you will be less likely to overeat. 

When combined with other healthy choices, such as exercising, eating more fiber can help maintain a healthy weight. 


It has been suggested that a diet with high fiber intake can help to lower the risk of breast cancer as well as colorectal cancer (2).  

Image of Veronica Rouse with Free 7 day heart healthy meal plan freebie.

What Is Oat Fiber?

Oat fiber is made by grinding the husk of the oat into a fine powder. The husk is the outer layer of the oat, which consists entirely of insoluble fiber.

The oats that we are used to seeing already have the husk removed, as it is inedible when on the oat grain. 

Nutritional Information

As mentioned above, oat fiber is made up entirely of insoluble fiber, which is not digested by our bodies. It passes through the digestive system without being broken down and adds bulk to our stool. 

Insoluble fiber helps to prevent constipation and may also help to lower LDL cholesterol and blood sugar (3).

Since insoluble fiber is not digested by the body, oat fiber is very low in calories and does not contain significant amounts of any other nutrients. Because of this, oat fiber is keto friendly. 

Uses In Cooking And Baking

Oat fiber can be used as a substitute for flour in recipes for baked goods. However, it is usually best used in a mixture with other types of flour rather than on its own since it absorbs a lot of water and may result in a dryer product if used alone. 

It can be used in recipes for baked goods such as breads, muffins, and cookies. It can also be used in granola, smoothies, or as a thickening agent in recipes such as soups. 

Can It Be Made At Home?

Oat fiber cannot be made at home as it would be very difficult to remove the husk from oat grains on your own. 

Time It Takes To Cook

When using oat fiber as a substitute in recipes, the cooking time should remain the same. 

Other Substitutes

  • Psyllium husk powder
  • Chia seed powder
  • Ground flaxseed powder

What Is Oat Flour?

Oat flour is made by grinding whole oats (with the husk removed) into a fine powder. 

In comparison to oat fiber, oat flour contains more nutrients aside from fiber since it is made from the whole oat. 

Nutritional Information

Oat flour contains both soluble and insoluble fiber and nutrients such as calcium, iron, and potassium.

In a serving size of ¼ cup (30g)(4):

  • 120 calories
  • 4g protein
  • 2g fat
  • 22g carbohydrates
  • 3g fiber

Taste And Texture

Oat flour has a mildly sweet and nutty taste. When used in baked goods it gives a softer, chewier texture. 

Uses In Cooking And Baking

Like oat fiber, oat flour can be used in any baked goods that contain flour and can be used as a substitute for all-purpose flour.

It can be used in recipes for baked goods such as muffins, cakes, pancakes and cookies. 

Can It Be Made At Home?

Oat flour can be made at home by blending oats into a powder consistency using a blender or food processor.

Time It Takes To Cook

Like with oat fiber, when using oat flour, cooking times should remain the same. 

Other Substitutes

Oat flour can be substituted with any other type of flour. 

Some other gluten free options:

  • Almond flour
  • Rice flour
  • Buckwheat flour
  • Coconut flour

What Is Oat Bran?

Oat bran is the outer part of the whole oat (with the husk removed) which is removed from the rest of the oat and used on its own.

Nutritional Information

The oat bran is where most of the nutrients in whole oats are found. It contains more protein and fiber when compared to oatmeal.

Oat bran is high in soluble fiber, which absorbs water in the digestive tract, helping with bowel function. 

Soluble fiber may also help reduce risk for heart disease and lower LDL cholesterol, blood pressure, and blood sugar levels (3).

In a serving size of 1 cup (94g)(5):

  • 231 calories
  • 16.3 g protein
  • 6.6 g fat
  • 62.2 g carbohydrates
  • 14.5 g fiber
  • Calcium, iron, magnesium, phosphorus, potassium, zinc, vitamin B6, thiamin (vitamin B1), riboflavin (vitamin B2), folate (vitamin B9)

Taste and Texture

Oat bran has a smoother and creamier texture compared to oatmeal; however, the taste is very similar. 

Uses In Cooking And Baking

Oat bran can be added into baked goods such as muffins and cakes. Or, it can be used on its own to make a hot porridge or overnight oat bransimilar to how we often use oatmeal. 

It can also be used as a topping on yogurt, cereal, or smoothies. 

Check out this article on oat bran recipes to lower cholesterol for other ideas of how to use oat bran and even more information on its health benefits. 

Can It Be Made At Home?

Oat bran can be made at home using a food processor or blender. 

First, take whole oats and pulse them into a course powder. Then, sift the powder to separate the bran, which can then be used on its own (6).

Other Substitutes

  • Wheat bran
  • Rice bran
  • Corn bran
  • Flaxseed 

What Is Oatmeal?

Oatmeal is made from different forms of oats, all of which consist of the whole oat grain. They all have the husk removed but are then processed differently.

Oat groats are the least processed form, with only the husk removed and no further processing done. 

There are also steel cut oats, rolled/old fashioned oats, quick oats, and instant oats.

Steel cut oats are made by using steel blades to cut oat groats into 2 or 3 pieces. 

Rolled/old fashioned oats are made by first steaming the oat groats, then rolling them out, resulting in a flattened oat.

Quick oats are made the same way as rolled oats; however, they are rolled even thinner in order to shorten the cooking time. 

Finally, instant oats are also made by first steaming and rolling the oats but are then pre-cooked and dried again so that the cooking time will be even shorter than for quick oats. One thing to watch for in instant oats is added sugars.  Choose one with the only ingredient as oats, if possible.

Nutritional Information

Since oats consist of the whole grain, they have both soluble and insoluble fiber. As mentioned earlier, fiber helps with digestion as well as lowering the risk for heart disease. 

In a serving size of 1 cup (234g) of plain cooked instant oats (made with water) (7):

  • 159 calories
  • 5.55 g protein
  • 3.18 g fat
  • 27.4 g carbohydrates
  • 3.98 g fiber
  • Calcium, iron, magnesium, phosphorus, potassium, zinc

Uses In Cooking And Baking

Oats can be used on their own to make hot porridge or overnight oats. They can also be added into baked goods.

Check out these 15 oatmeal recipes to lower cholesterol article that is filled with ideas of how to incorporate oats into your diet!

Other Substitutes

  • Amaranth
  • Barley
  • Buckwheat
  • Quinoa 

Oat Fiber vs Oat Flour vs Oat Bran vs Oatmeal: Which One To Use?

Nutritional Values Comparison

Below is a table comparing the nutrient values for the four oat products. Note that the serving sizes differ based on the typical serving size people consume. 

 Oat fiberOat flourOat branOatmeal
Serving Size1 tsp¼ cup1 cup (raw)1 cup (cooked)
Protein0g4.0g 16.3g5.5g
Carbohydrates3g 22.0g62.2g27.4g
Fiber3g3.0g 14.5g4.0g

When To Use Oat Products

Oat fiber and oat flour can both be used as a substitute for flour or mixed with other flours in baked goods. They should be added according to the recipe, at the same step that the flour would be added. 

Oat bran and oatmeal can both be used on their own to make hot porridge or overnight oats/oat bran. They can also be added to baked goods, and oat bran can be used as a topping for yogurts and smoothies. 

How To Incorporate Oat Products Into Your Diet

Final Thoughts

As you can see, oat products have many uses and are great for you, not to mention great tasting too!

I hope this article provided you clarity on the differences between oat fiber vs oat flour vs and oat bran vs oatmeal.

They contribute to heart health, digestion, blood sugar, and body weight, mainly due to their high fiber content. 

Try adding them to your already loved recipes or try out some of the recipes mentioned throughout the article for delicious ways to include more oats in your diet!

Let me know in the comments what was the most interesting thing you learned from the article!

This article was written by Siobhan Tyler, Nutrition Student, and Veronica Rouse, MAN, RD, CDE.

Image of Veronica Rouse with Free 7 day heart healthy meal plan freebie.

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