Whole Grains vs. Refined Grains

Medically reviewed by Allison Herries, RDN

Grains and grain products consist of wheat, oats, rice, corn, and other cereal grains and products made with them. Grains are divided into two categories: whole grains and refined grains.

Whole grains are generally considered more nutritious than refined grains as they're higher in fiber and are linked to many health benefits.

Though whole grains should be prioritized over refined grains as they help promote blood sugar control, digestive health, and satiety, you don't have to completely avoid refined grains to maintain optimal health.

What Are Whole Grains?

A grain kernel consists of three parts, the germ, the endosperm, and the bran. Whole grains are grains that contain all three parts of the grain kernel. The bran and germ contain important nutrients, such as fiber, B vitamins, and magnesium, which makes whole grains more nutritious than refined grains, which have had their germ and bran removed.

Examples of whole grains include brown rice and whole oats. Whole grain products include whole wheat flour and whole grain pasta.

A product that qualifies as a whole grain in the United States must contain 100% of the original grain kernel. Products labeled as whole grain, such as flour and cereal, must contain at least 8 grams of whole grain per 30 grams of product.

Whole grains contain significantly more fiber than refined grains, as most of the fiber in grains is found in the bran or outer layer of the grain kernel. Whole wheat flour contains up to 600% more fiber than refined white flour.

Fiber helps slow digestion, which supports feelings of fullness and promotes healthy blood sugar regulation. It also helps your body keep cholesterol levels in check and is important for digestive health, as it helps reduce constipation and encourage a balanced gut environment.

Whole grains may benefit health in several ways, including protecting against chronic health conditions and obesity. Studies show that people who follow diets rich in whole grains have a lower risk of developing certain diseases, such as heart disease, some cancers, and type 2 diabetes. People who eat whole grains seem to be at a lower risk of developing obesity and gaining weight over time compared to people who eat refined grains.

What Are Refined Grains?

Refined grains and refined grain products include white rice, white bread, white flour, and foods made with white flour, such as crackers, pasta, and cookies.

Refined grains are lower in nutrients than whole grains as refined grains are milled, which is a process that removes the bran and germ. Though the milling process results in grains with a longer shelf life and finer texture, it also removes important nutrients such as iron, B vitamins, and fiber.

Some refined grain products are enriched with certain vitamins and minerals, like folic acid and iron, which makes them more nutritious than unenriched refined grains. However, fiber isn't added back to refined grain products. Because of this, people who rely on refined grain products tend to have a lower fiber intake, which can affect many aspects of health such as blood sugar regulation, blood lipid levels, and body weight.

Research shows that people who follow diets high in refined grains are more at risk for developing certain health conditions like obesity and metabolic syndrome, a cluster of symptoms including high blood sugar and high blood pressure that increases the risk for heart disease.

Because they're low in fiber, refined grains are less filling than whole grains and are easier to overeat. This may be why people who consume more whole grains are less likely to be obese than people who eat more refined grains.

How Does the Nutrition Compare?

Whole grains are generally more nutritious than refined grains as they provide more fiber and are naturally higher in certain vitamins and minerals.

Here's the nutritional breakdown of a one-cup serving of cooked brown rice, which is considered a whole grain, compared with the same serving of cooked unenriched white rice:

White rice, which is considered a refined grain, has gone through processing that removes the bran and germ from the grain kernel. This results in a less nutritious and less satiating (filling) product. It's lower in protein, fiber, B vitamins like folate, and minerals such as magnesium, zinc, and iron.

Enriched white rice, as well as other enriched refined grain products like white flour, has nutrients added back during processing, including folic acid and iron. Research shows that enriched refined grain products, such as ready-to-eat cereals, help children and adults in the United States meet their daily needs for several essential nutrients, such as iron.

One cup of enriched white rice can cover as much as 15% of the DV for iron and over 40% of the DV for folate. These nutrients are commonly under-consumed by U.S. adults and children. Therefore, enriched refined grains can help boost the intake of some nutrients.

Which Is Better for Health?

Whole grains are much more nutritious, providing higher levels of fiber, health-promoting antioxidants, and several vitamins and minerals compared to refined grains. They have been shown to benefit health by protecting against common health conditions like heart disease, colon cancer, and type 2 diabetes.

Refined grains have been associated with increased health risks, including metabolic syndrome and poor blood sugar regulation.

Enriched refined grains have been shown to help children and adults meet their daily needs for certain nutrients, like iron. Consuming them occasionally won't significantly impact health. However, regularly consuming refined grain products, like cakes, sugary cereals, and cookies made with white flour, might contribute to health risks like high blood sugar levels and weight gain.

Just because a product is considered whole grain doesn't necessarily mean it's a nutritious choice. For example, though cookies made with whole grain flour will be richer in fiber, they're still high in calories and added sugar. Another example is whole grain cereals, which can be packed with added sugar, depending on the type.

How to Balance Whole and Refined Grains

Grains are considered a type of carbohydrate, which is one of the three macronutrients your body needs daily. While carbs are important for health, your carb needs depend on several factors, such as your body weight, activity levels, and blood sugar control.

It's generally recommended that adults take in between 45-65% of their daily energy needs in the form of carbs like grains, starchy vegetables, beans, and fruit. However, it's important to note that there's no ideal carbohydrate intake level, and some people may thrive on lower-carb diets.

Whole grains are an example of a nutritious carb choice. The USDA recommends that at least half of your daily grain intake come from whole grains. Unfortunately, though most Americans consume a lot of grain products, they're mostly in the form of refined grains.

Choosing more whole grain products as well as other healthy carb sources like vegetables, fruits, and beans, can help you meet your nutrient needs and may reduce your risk of several common health conditions. While whole grains can be a nutritious choice, it's also important to consume plenty of protein and healthy fats.

Though refined grains should be limited and replaced with healthier options like whole grains, vegetables, fruits, and protein sources whenever possible, they can still be enjoyed on occasion without harming your health, especially if the rest of your diet is composed of nutrient-dense foods.

A Quick Review

Whole grains contain the entire grain kernel and are generally more nutritious than refined grain products. Choosing whole grain products over refined grains can help you meet your daily nutrition needs and may also lower your risk of several health conditions, including colon cancer and type 2 diabetes.

While whole grains are generally recommended over refined grains, refined grains are unlikely to negatively affect health if they're consumed sparingly as part of a well-balanced diet.

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