What Are Refined Carbs — and Should You Avoid Them? Dietitians Explain

Refined carbs have gotten a bad rap over the years, much to the dismay of carb-loving girlies everywhere. But what are refined carbs, exactly? Also known as simple carbs, these carbohydrate sources have two categories: sugars and refined grains.

Some examples of refined grain products include white bread, white rice, and white flour. Table sugar and corn syrup are two examples of refined sugars. Refined carbs have gotten a negative reputation because they tend to be ultra-processed. And during the processing stage, certain compounds (like the bran and germ of a whole grain) are removed, resulting in a less nutritious food choice than their original counterpart.

But does the refining process mean that you have to live in a world without a sesame bagel at your Sunday brunch or sans a snack-sized bag of pretzels when you are on a flight? And is it really that bad to add refined sugar to your sweet tea? Here, registered dietitians — myself included — clear up the conundrum.

Refined carbs come in two forms: refined grains and sugars.

Refined grains are made when whole grains undergo a process where certain parts of the grain are removed. Whole grains consist of three key parts, according to Harvard's T.H. Chan school of Public Health. This includes the bran, germ, and endosperm. The bran is the outer skin of the grain, containing antioxidants, B vitamins, and fiber. The germ is the part that has the potential to sprout into a new plant, and it contains many B vitamins, protein, minerals, and healthy fats. The endosperm, the largest part of the grain, contains starchy carbohydrates, proteins, and small amounts of vitamins and minerals.

When grains are refined, the process removes the bran and germ, leaving only the endosperm. Although this process increases the grain's shelf life, it also strips away a significant proportion of the nutritional value. The remaining endosperm contains mostly carbohydrates and small amounts of protein, making refined grains less nutritious than their whole grain counterparts.

In the case of sugar, the process starts with raw materials such as sugarcane or sugar beets that are crushed to extract their juice. This juice is then boiled to produce a concentrated syrup, which is processed further to remove impurities. The resulting substance is then crystallized and centrifuged to yield a white, refined sugar product. This refining process depletes the sugar of its naturally occurring nutrients, and the final product is almost 100% pure sucrose. The simplicity of this molecule means it is quickly absorbed into the bloodstream, potentially resulting in a rapid spike in blood sugar and insulin levels.

Eating too many refined carbs is indeed linked to an increased risk of obesity, heart disease, and other negative health outcomes, including metabolic syndrome and type 2 diabetes. And refined sugar intake is also linked to outcomes like an increased risk of dental cavities.

But that doesn't mean you have to kiss your favorite pasta or white rice-based dish goodbye if you are trying to support your health. Research-based dietary guidelines, including the Dietary Guidelines for Americans, 2020-2025, suggest that consumers "make half your grains whole", meaning that at least 50% of the grains consumed should be from a whole grain source.

Following this guideline means that as much as 50% of the grains we consume can be from refined sources. While it is true that refined grains are lower in fiber and antioxidants, some countries (including the US) enrich refined grains, adding micronutrients (like certain B vitamins and iron) to replace some of the losses that occur during the refining process.

Ultimately, when it comes to refined carbs, it's all about balance. "I don't think people have to completely avoid refined carbs unless they find that they can't control their consumption," says Lisa Andrews, MEd, RD, LD, a registered dietitian and owner of Sound Bites Nutrition. Another sign to cut back on refined carbs is if you notice high blood sugar levels, Andrews adds.

Otherwise, the occasional morning croissant or afternoon doughnut won't make or break your health. "As long as the remaining calories in your diet come from a variety of nutritious, whole foods like fruits, vegetables, whole grains, low-fat dairy products, nuts/seeds, beans, and lean animal protein," Andrews says.

That being said, when it comes to eating refined carbs, especially if you have preexisting medical condition (like diabetes), it's best to consult your doctor or dietitian about your specific needs for a healthy diet and lifestyle.

Here are some common examples of refined carbohydrates that you might find in your diet:

Many of these foods provide affordable and accessible nutrients, and fortified options provide important B-vitamins and iron.

It's important to note that consuming these foods in moderation is unlikely to harm your health, but they should not make up the bulk of your diet. Try to swap them out for whole grain alternatives and foods with natural sugars, like fruits and vegetables, whenever possible. And if you do choose refined grains, try pairing them with a healthy fat, fiber, and/or protein source to help slow down the digestion process, causing a more gradual release and absorption of glucose from carbohydrates. This helps to prevent the rapid blood sugar spikes and crashes associated with consuming refined carbohydrates alone.

Andrews reminds us that "refined carbs, like white rice, are a staple in several cultures and should be enjoyed."

Opting for complex carbohydrates is generally encouraged to make up the bulk of your diet. These carbs are slower to digest, provide a steady release of energy, and are typically richer in nutrients. Here are some examples of complex carbohydrates to include in your diet:

Remember, a balanced diet is key to maintaining good health. These carbohydrate-rich foods, combined with a good mix of proteins and fats, can provide all the nutrients your body needs.