How bad are carbs, really?

 There is a fear that carbohydrates are detrimental to health. As a result, low carb diets have become popular, especially for weight loss. In this Honest Nutrition feature, we explain what carbohydrates are, look at healthy vs. unhealthy options, and discuss whether a diet rich in

Carbohydrates are considered essential nutrients for the body to function properly by several global health organizations, including the World Health Organization (WHOTrusted Source). Their primary role is to provide energy to all cells in the body. In the absence of carbohydrate intake, the body will use an alternative fuel source called ketones.

The word “carbohydrate” is an umbrella term that describes various types of sugar-containing molecules present in foods.

Types of carbohydrates

Generally, there are three types of carbohydrates: sugars, starches, and dietary fiber.

It is possible to classify them further as simple or complex carbs, depending on the number and type of sugar molecules — such as glucose — that each structure contains.

Simple carbs

Also called “simple sugars,” “sugars,” or “saccharides,” these carbohydrates contain between one and 10 sugar molecules and are present in fruits, vegetables, and dairy products. Those with one or two sugar molecules are called monosaccharides and disaccharides, respectively, while those containing up to 10 sugar molecules are called oligosaccharides.

Lactose — the main sugar in animal milk — is a disaccharide comprising the monosaccharides glucose and galactose.

Oligosaccharides, however, are mid-length prebiotic carbohydratesTrusted Source that are in fiber-rich foods and human milkTrusted Source.

Complex carbs

Complex carbohydrates are made up of polysaccharidesTrusted Source, which are longer, intricate chains of sugar molecules. Complex carbs include both starches and dietary fiber.

Starches are the storage carbohydrates in peas and beans, grains, and vegetables, and they provide the body with energy.

Dietary fiberTrusted Source, or roughage, is the indigestible part of plants — in whole grains, fruits, vegetables, nuts and seeds, and legumes such as peas and beans — that supportsTrusted Source good gut health.

Are there ‘healthy’ and ‘unhealthy’ carbs?

Carbohydrates often get a bad rap due to the associationTrusted Source of their excessive consumption with weight gain, obesity, metabolic syndrome, and diabetesTrusted Source.

This phenomenon, which some researchers call “carbotoxicityTrusted Source,” promotes the idea that the excessive consumption of all types of carbohydrates favors the development of chronic diseases.

For this reason, many low carbohydrateTrusted Source diets have become popular among people interested in losing weight or managing blood sugar levels. They are even in favor among seasoned athletesTrusted Source.

However, several other studiesTrusted Source have demonstrated that the qualityTrusted Source of carbohydrates that people consume is as important as the quantity.

This finding suggests that rather than all carbs being “created equal,” some options are better than others for health.

‘Unhealthy’ carbs

Carbohydrates that people may consider unhealthy because they are less nutritious include:

• refined carbohydrates, such as polished rice and flour

• sugar-sweetened beverages, such as sodas and juices

• highly processed snacks, including cookies and pastries

According to existing research, a diet with a higher intake of these types of carbohydrates and fewer of the more nutritious options can increase markers of inflammationTrusted Source and perpetuate hormonal imbalancesTrusted Source in people with polycystic ovary syndrome (PCOS).