What you should know about refined carbs, according to a dietitian

I’m a big carbohydrates gal. When a restaurant brings out its bread basket, more often than not I’ll fill up before the main course even arrives—and be happy about it. That said, I’m also aware of the nutritional discourse throughout the years making carbs out to be the “bad guy” (side note, this is a phrase we should throw in the trash anyways).

Granted, carbs are essential for our bodies to create energy, and whole grains are often touted by health and nutrition experts for their high fiber and phytonutrient content. Yet, often in the same breath, experts also call out something called refined carbs as being highly processed, stripped of most of their nutrients, and generally not that great for health. It’s confusing.

However, not all RDs are buying into the fear-mongering around refined carbs (and carbs in general, TBH.) “I wouldn’t say [refined carbs] are evil, and I really don’t like the ‘good versus bad.’ It’s different,” says Jessica Levinson, RDN, CDN.

So what are refined carbs, exactly? Essentially, they’re carbohydrate foods that have been stripped via processing of their extra nutrients (like fiber, vitamins, and minerals). If you broke down a grain kernel, for example, you’d find three layers. The outer layer, or bran, is packed with fiber and B vitamins. The germ, or the small, inner core, contains nutrients like zinc, magnesium and vitamins B and E. The rest of the kernel is called the endosperm, which is ultra starchy. “A whole grain has the bran, the germ, and the endosperm intact,” says Levinson. “A refined grain has the bran and the germ processed off, so all that’s left is the starchy part.” Some examples of refined carbs include white flour, white pasta, sugar, and white bread.

How do refined carbs affect the body?

Refined carbs typically lack the extra nutritional benefit of their whole grain or complex carbohydrate counterparts. Think of the brown versus white rice debate. Brown rice, which has all three layers of the whole grain intact, offers up three grams of fiber per cooked cup. Compare that to a serving of cooked white rice, which only has 0.6 grams of fiber. Other important minerals you might miss: B vitamins like niacin, riboflavin, and thiamin, or minerals like iron.

Refined carbohydrates also generally take less time for your body to digest, which sounds like a good thing but really isn’t. With refined carbs, “your body is not doing that processing, because a machine has already done it,” Levinson says. That means all that’s left is for your body to digest the sugar. As glucose enters the bloodstream more quickly, blood sugar inflates faster. “[A refined carb] doesn’t have the fiber to slow down the processing in the body,” she says.

Plus, refined carbs are typically found in processed foods, which are not that beneficial for your health. In fact, a small study published in May of this year found that a diet high in processed foods can lead to overeating and unwanted weight gain—even when consuming meals equivalent in macros to people eating a non-processed diet. “When you match the diets for all of those nutrients, something about the ultra-processed foods still drives this big effect on calorie intake,” lead author Kevin Hall, PhD, told NPR.

So…are all refined carbs as bad as everyone says?

“People think anything that is processed is bad,” Levinson says. That’s not the whole truth. Levinson notes the 2015-2020 Dietary Guidelines for Americans suggest getting at least half of your grains from whole grains. “There’s room in there for you to have a combination of both whole and refined,” she says.

Speaking of carbs, why are people so freaked about gluten? An RD breaks it down:

Certain refined grains are also enriched post-manufacturing, so they’re not all devoid of nutrients. “They’re fortified afterwards with nutrients that are lost,” Levinson says. However, while enriched grains can contain B vitamins like folate, fiber typically isn’t added back. (And of course, these are processed into order to add back these nutrients.)

The aim, of course, is to get your energy from unrefined carbohydrates that will feed your body with nutrients and without nasty blood sugar spikes or dips. And because of their impacts on blood sugar, refined carbohydrates should really be eaten in moderation. But at the end of the day, striking a balance between mostly complex carbs like whole grains (with some refined carbs in the mix) is completely acceptable, rather than turning it into an unhealthy obsession.

How to spot refined carbs in grain products

If you’re shopping for products other than literal grains (like farro, for example), you’ll want to peek at the ingredient list first. Ideally, the first ingredient will be “whole grain,” your cue that it contains unrefined grains.

“If you’re looking at a package of bread and the first ingredient is wheat flour, that is not the same as whole wheat flour,” Levinson says. Wheat and rye flour are made of milled grains, aka refined. Products with these flours make up most of the refined carbs we consume. This processing helps increase shelf life and adds a fluffier texture, but it won’t do favors for your body. Oh, and as for all-purpose flour? It’s just bleached wheat flour.

Levinson also suggests looking at the fiber content, as it’ll hint towards if the grain is refined or not. You’ll want to grab for the product with higher fiber content, since it can mean the grain used still contains its outer layer. Keep in mind though, fiber can be added into a product through different sources beyond grain.

Flash to the grocery aisle when you’re picking out bread. It’s decision time, and your heart might say one thing, but the RDN in your head might say another. “You’re better off with the whole wheat bread for the nutrients from the whole grain and fiber,” Levinson says. Roger that.

Looking for foods that are high in fiber but low in carbs? Step right this way. And if you’re looking for an eating plan that embraces carbohydrates, you might like the Mediterranean diet.