How you can reduce the refined carbs in your diet

Carbohydrates are one of three macronutrients — alongside fat and protein — and they’re your body’s primary energy source. 

When you eat carbs, your body breaks them down into simple sugar molecules, mainly glucose. These sugar molecules enter your bloodstream and serve as energy for your cells. 

Refined carbohydrates are carbs that have had most of their nutrients removed during processing.

Research indicates that diets with large amounts of refined carbs aren’t good for metabolic, heart, brain, or mental health. Still, the average Western diet includes an excessive amount of refined carbs.

In this article, we’ll explore how refined carbs affect your body and overall health. We’ll also look at some common sources of these carbs and describe how to swap them for more nutrient-dense options.

ZOE runs the largest nutrition science study in the world, with more than 50,000 participants so far. We’ve found that how your body responds to refined carbs is unique to you.

With ZOE's personalized nutrition program, you can learn how your body responds to foods and how to eat for your long-term health.

Take our free quiz to get started.

Different types of carbs

There are three types of carbohydrates — simple carbs, starches, and fiber. Many whole foods contain a mix. 

Simple carbohydrates 

Simple carbs are made from one or two sugar molecules. These sugars can reach your bloodstream quickly, and your cells then take them up for energy. 

Because it doesn’t take very long to digest simple carbs, eating foods that contain lots of these sugars can lead to spikes in blood sugar levels in some people.

A lot of foods that aren’t very nutritious, like sugary drinks and candies, are high in simple carbs, mostly in the form of added refined sugars, like table sugar and high-fructose corn syrup. 

Some healthy foods — like whole fruits, milk, and other dairy products — naturally contain simple carbs, along with many other important nutrients.

Because these simple carbs are naturally present in the complex structure of the food, they’re less likely to cause big rises in blood sugar.


Starches, like fiber, are a type of complex carbohydrate.

As you might expect, complex carbs have a more complicated structure than simple carbs. This means that it takes your body longer to break them down into smaller sugars and absorb them. 

Since this process takes longer, you typically end up with a more gradual rise in blood sugar than you get with simple carbohydrates.

Whether a starchy food is more or less nutritious depends on how much processing or refining it undergoes. 

Whole grains are a type of whole starchy food and are good for your health. White bread made with refined white flour, on the other hand, is a type of refined, starchy food. It’s a less healthy option because it lacks many useful nutrients. 

Good sources of healthy starches include:

  • whole grains, such as oats, barley, brown rice, and quinoa

  • legumes, such as beans and lentils

  • vegetables, such as potatoes, broccoli, and spinach 

  • nuts and seeds, such as almonds, walnuts, sunflower seeds, and pumpkin seeds


Fiber is another type of complex carbohydrate. But unlike starches, your body can’t digest it.

Although it doesn’t directly provide energy, fiber is incredibly important for your overall health. It promotes regular bowel movements and is beneficial for your gut health.

Some fiber also acts as food for the trillions of microbes living in your gut, collectively called the gut microbiome.

How to swap out refined carbs

Swapping out refined carbs for unrefined carbs can be a great way to promote your overall health.

Researchers have associated a higher intake of whole grains — but not refined grains — with better blood sugar control, body weight, and fat distribution. 

Here are some quick swaps you can try to build a more nutrient-dense diet.

Source of refined carbsFood swap
white breadwholegrain bread
white ricebrown rice, cauliflower rice, quinoa
most pastaswholegrain pastas
sugary drinksherbal teas
ultra-processed snacks, like potato chipsnuts, like almonds and cashews
candiesberries, dark chocolate

What are refined carbs?

Refined carbs are carbs that have been through a manufacturing process that has removed many of their health-promoting nutrients and compounds.

Carbs are made up of sugars, but they can also contain fiber, vitamins, minerals, and polyphenols. The manufacturing, or refining, process removes these.

For example, whole grains, like wheat, have three main parts: the bran, endosperm, and germ. 

The bran and germ contain plenty of vitamins, minerals, antioxidants, fiber, and other healthful compounds. The endosperm is easily digestible, but it contains fewer nutrients.

The refining process removes the bran and germ, leaving just the endosperm. This means you end up missing out on most of the helpful nutrients. 

By choosing whole grains, you’re getting more fiber and nutrients, like vitamins E and B12, iron, zinc, and magnesium.

Health impacts of refined carbs

Eating too many refined carbs isn’t good for your health. Still, refined carbs make up a large part of the average Western diet.

Research suggests that diets high in refined carbs may increase the risk of many health conditions, including those relating to:

Blood sugar spikes

When you eat refined carbs, your body breaks them down quickly into simple sugars, leading to a rise in your blood sugar level. 

A blood sugar increase after you eat is normal. But if your blood sugar is frequently very high, this can lead to chronic health conditions, like prediabetes and type 2 diabetes.

A sharp rise in blood sugar can lead to a dip — or a blood sugar crash — that can leave you feeling hungry and tired.

Although certain foods, like white bread, are more likely to lead to a blood sugar spike, this isn’t the case for everyone. In fact, how your body responds to any food is unique to you.


There are three main types of carbohydrates: simple carbs, starches, and fiber. 

Carbs are an important energy source, but the quality of your carb-containing foods is key when it comes to your long-term health. 

Refined carbohydrates have gone through a manufacturing process that removes most of their nutritional value. This means you can lose out on fiber, vitamins, minerals, and polyphenols.

Some common sources of refined carbs include white bread, white rice, and ultra-processed snacks, like potato chips and candy.

Swapping out some refined carbs for unrefined versions can make a big difference in your diet.

For many people, eating refined carbs is likely to lead to large blood sugar rises, but each person’s response is unique. 

With the ZOE at-home test, you can learn about your own blood sugar and blood fat responses, as well as which “good” and “bad” bugs are living in your gut. 

Take our free quiz to get started. 


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