What to Know About Carbs

Medically Reviewed by Poonam Sachdev on June 22, 2021
4 min read

‌Many people have a love–hate relationship with carbohydrates, which are otherwise known as “carbs.” They love the way popular carbs, such as bread, pasta, potatoes, and rice taste. But people tend to blame these foods if they gain weight or have health issues. 

However, carbs aren't all good or all bad. Most foods contain carbs, and they are a good source of the fuel your body needs to function. 

Carbohydrates are a macronutrient, meaning that they are needed in relatively large amounts. The other two macronutrients are fat and protein. As opposed to macronutrients, micronutrients are nutrients that you need in small quantities and they include vitamins and minerals.

Carbohydrates can be simple or complex. Complex carbohydrates often contain fiber, vitamins, minerals, and other valuable nutrients. They’re slower to digest.

Simple carbohydrates digest quickly and can raise blood sugar, causing weight gain.

If you have certain health conditions, you may need to count your carbs. Guidelines from the U.S. Department of Agriculture say that most people should get about 130 grams of carbohydrates a day, amounting to about 45% to 65% of their total calories for the day.  

Most of these calories should be in the form of healthier complex carbohydrates.

Many foods contain carbohydrates, which come in three main forms:

Sugars. All sugars are simple carbohydrates. Sugars occur naturally in many foods. Fruits contain fructose, while milk and some dairy products contain lactose. Food companies add sugar to many food products.

Starches. Starches are complex carbohydrates formed of many sugars joined together. Most vegetables and grains contain starch, and so do beans and peas, which are also called legumes.

Fiber. Fiber is another complex carbohydrate. Your body cannot break it down, so fiber passes through the digestive system and is thrown out via stool. Only plants contain fiber. Particularly, fruits, vegetables, beans, peas, and whole grains are good sources of this complex carb. 

Carbohydrates are important in your diet for the following reasons:

They provide energy. Carbohydrates break down into glucose, the body’s main fuel. Neither protein nor fat is as efficient of a source of energy as carbs.

Carbs in whole foods have many nutrients. Fruits, vegetables, and whole grains supply many vitamins and minerals. They also contain plant compounds called phytonutrients, which can prevent disease.

Complex carbs give you fiber. Besides aiding in digestion, fiber can lower cholesterol and stabilize blood sugar. Increasing fiber in your food can lower your risk of heart disease and several types of cancer.

Complex carbs can help you maintain ahealthy weight. Because they are bulky, many healthy sources of carbs help you feel full, which makes you eat less. There is very little evidence that healthy carbs contribute to weight gain.

Those who want to lose weight are often steered toward a low-fat or low-carb diet. People may lose weight when on either of the diets, but some studies have shown that you may lose more body fat on a low-fat diet.

Researchers aren't sure whether low-carb diets are good for your overall health. Low-carb diets that contain a lot of saturated fats can be bad for your heart.

Also, some of the weight lost on low-carb diets is probably only water weight, not body fat.

The best diet is a long-time topic of debate. Many studies rely on what people said they ate. But in two studies backed by the National Institutes of Health, participants were asked to stay on site and eat only the food provided to them.

In a 2015 study, people with an obese BMI were asked to spend five days on a baseline diet. They were then switched to either a low-fat or low-carb diet. The participants then went home for a few weeks and then returned to repeat the process with the opposite diet. Here, the participants lost weight on both diets but lost more body fat on the low-fat diet.

In a 2021 study, 19 people spent two weeks on either a low-carb or a low-fat diet, before changing to the other one. They could eat as much of the supplied food as they wanted. Here, the participants ate less and lost more body fat on the low-fat diet than they did on the low-carb diet.

If you have diabetes and you’re watching how many carbs you eat, it’s helpful to know about the concepts of glycemic index and glycemic load:

Glycemic index. The glycemic index ranks foods according to how quickly their carbs are converted to sugars. Foods with a high glycemic index can cause blood sugar to spike. These foods may be related to heart disease, obesity, and other health problems, including diabetes.

Glycemic load. The glycemic index does not consider the number of carbs per serving of a particular food. To address this, a different measurement, called the glycemic load, is used. This measurement is more useful for those striving to make good food choices.

Foods with a high glycemic load should be eaten sparingly. These foods include the following:

  • Candy bars
  • Highly processed breakfast cereals
  • French fries
  • Baked potatoes
  • White rice

Healthier choices include foods with a lower glycemic load like the following: