Carbohydrates are a component of food that supplies energy through calories to the body. The energy value of digestible carbohydrates is four calories per gram. Along with proteins and fats, carbohydrates are one of the three macronutrients that your body needs.

There are different types of carbohydrates—some are found naturally in food and others are manufactured to be included in processed foods. Examples of carbohydrate foods include grains, fruits, cereals, pasta, bread, and pastries.

Learn about the different types of carbs to make healthier food decisions.

Types of Carbohydrate

Carbohydrates are made of carbon, hydrogen, and oxygen and they are classified in different ways. The most exact way is by chemical structure: Sugars classified as monosaccharides and disaccharides and more complex carbohydrates as polysaccharides or oligosaccharides.

There are three basic types of carbohydrates found in food, with a fourth category as well.

Sugars

Also called "simple carbohydrates," these are molecules of simple sugars such as glucose, fructose (fruit sugar), and galactose, which are known as monosaccharides.

When two of these molecules join together, they are called disaccharides. An example of a disaccharide is sucrose—or table sugar—which is made up of molecules of glucose and fructose. Lactose (milk sugar) is another example. Lactose is glucose and galactose joined together.

Starches

Starches are polysaccharides or "complex carbohydrates," composed of long chains of glucose. Your body breaks down starches—some more rapidly than others—into glucose to produce energy.

A special starch, called resistant starch, may be especially valuable for weight loss and colon health.

Fiber

Fiber is a carbohydrate found in the cellulose of plant-based foods such as grains, fruit, vegetables, nuts, and legumes. Dietary fiber can be soluble or insoluble and passes through the body without being fully digested. This means that fewer calories are absorbed by the body, although research is ongoing about exactly how many calories different types of fiber contribute.﻿﻿

Fiber is not used for energy by the body and so the grams of fiber are often listed separately under the carbohydrate category on nutrition labels. While dietary fiber is not used for energy, it has a beneficial role in digestion and metabolism.

Oligosaccharides

This fourth category of carbohydrates falls between sugars and starches. Oligosaccharides are a fermentable combination of simple sugars that have positive effects in our colon and are considered prebiotics.

Daily Recommendations

Your age, sex, height, and weight factor into the daily recommendation for the number of calories and carbs you should eat every day. Your physical activity level will also play a big role: The more active you are, the more energy you burn, and the more calories you need.

In general, the USDA Dietary Guidelines for Americans recommends that men consume between 2,000 and 3,000 calories per day. Men who are younger and more active need more calories. Older men and those who are less active need fewer calories. Women generally need 1,600 to 2,000 calories per day.﻿﻿

It is further recommended that 45 to 65 percent of those calories come from carbohydrate. For a 2,000 calorie diet, that would be about 900 to 1300 calories from carbs or 225 to 325 grams of carbohydrate.

High- and Low-Quality Carbohydrates

Sometimes people refer to "good" carbs and "bad" carbs. Often, complex carbohydrates are considered "good," and simple and refined carbs are considered "bad."

While there are some carbohydrates that provide greater nutrition, it's not always helpful to refer to any food as good or bad.

It can be beneficial to understand the characteristics of complex, simple and refined carbs to understand how each might fit into your eating program.

Complex Carbohydrates

Complex carbs contain at least three sugars. Oligosaccharides contain between three and ten simple sugar units. Polysaccharides can contain hundreds of saccharides.

Complex carbohydrates such as legumes, whole grains, starchy vegetables, pasta, and bread provide the body with relatively sustained energy.

Simple Carbohydrates

Simple carbs are made up of only one (monosaccharide) or two (disaccharide) sugar units. Simple sugars include fructose, sucrose, glucose, maltose, and lactose.

Simple carbs include the carbs found in table sugar, candy, honey, and syrups; they provide quick energy.

Refined Carbohydrates

Refined carbs generally refer to the carbs are found in processed foods and beverages. These foods often include added sugar, fat, sodium, and preservatives to improve taste or shelf life.

Though they may be artificially fortified with vitamins and minerals, these foods often lack the nutrients available in whole foods. Foods like processed baked goods, processed potato products, and candy fall into this category.

Choosing the Best Carbs

According to Harvard Medical School, it is the quality of the carbohydrates you ingest that contributes to a healthy diet. For instance, low-quality carbs are quickly digested, often leading to blood sugar spikes and only a temporary feeling of fullness. The fiber and nutrients found in whole foods can offset the glucose conversion of starches and sugars, preventing drastic energy spikes and satiating the appetite.

In the Dietary Guidelines 2015–2020, the Office of Disease Prevention and Health Promotion recommends shifting to eat more vegetables, fruits, whole grains, and dairy to increase consumption of calcium and dietary fiber. They also recommend shifting away from added sugars in drinks, snacks, and sweets.﻿﻿

To improve the quality of carbs in your diet, choose more whole grains and limit foods that have added sugars. Cooking food from scratch at home and eating primarily whole foods, rather than processed ones, can help significantly.

Myths About Carbs

The popularity of some fad diets and other sources of misinformation have led to the promotion of certain myths about carbs.

Carbs Cause Weight Gain

Many people choose to go on a low-carb diet to lose weight. While some low-carb diets are effective for some people, it doesn't mean that carbs cause weight gain.

Excess calorie consumption causes weight gain. Consuming certain types of carbohydrates can indirectly contribute to the overconsumption of calories.

For example, if you eat a breakfast full of heavily processed sugary foods, you may get hungry shortly after eating and eat again. Whereas, choosing a breakfast that includes fiber and protein helps you to stay full and satisfied so that you don't eat again until lunchtime.

Low-Carb Diets Are Most Effective

Many people choose to go on a low carb diet to lose weight or to manage a medical condition such as type-2 diabetes. For them, a low carb eating style is the best way to achieve health or wellness goals.

But studies have shown that the most effective weight loss diet for you is the diet you can stick to for the long-term.﻿﻿ In short, there is no "best" diet. And even when you are managing a medical condition, you need to find a program that you will adhere to.

Many people see benefits when they follow a low-carb eating program because they eliminate foods that are less healthy, such as candy, sugary beverages, and processed foods.

Carbs Are the Body's Only Source of Fuel

The primary use of carbohydrates in the body is energy, but carbohydrates are not the only dietary source of it. Fats can not only provide energy, but they are also the main way the body stores it. According to the Institute of Medicine's Dietary Reference Intakes guide, you can live without eating any carbs as long as you eat adequate amounts of protein and fat:﻿﻿

"The lower limit of dietary carbohydrate compatible with life apparently is zero, provided that adequate amounts of protein and fat are consumed."

Your body can make the amount of glucose needed to survive (the Institute of Medicine estimated this to be about 22 to 28 grams per day) in a process called gluconeogenesis. It is a synthesizing of glucose, primarily from proteins.

A Word From Verywell

With some attention to the foods you eat, it is possible to have a healthy diet with fewer carbohydrates than the sugary and starchy diet often consumed today. A few simple changes can go a long way, lead to weight loss, and improve your overall health.