Esta guía en Español Young men's version of this guide

Carbohydrates, sometimes called “carbs”, are a source of energy found in grains, fruits, vegetables, and dairy foods. Carbs supply your body with the glucose (sugar) it needs for energy. Extra glucose is stored in your muscles and liver as glycogen, your body’s quick source of energy. After glycogen stores are filled, glucose is then stored as fat, your body’s energy reserve.

Carbs are divided into two types: simple and complex.

Simple carbohydrates (also called sugars) are absorbed quickly by the body and will give you fast energy. Sugars taste sweet and are found naturally in some nutritious foods like fruits and milk. Other times sugars are added to foods (also known as added sugars) that often have less nutritional value. Foods with high amounts of added sugars include soda, cookies, candy, and sugary cereal (or cereal with more than 8 grams of sugar per serving). The nutrition facts label will soon distinguish between added and natural sugars. For now, you can look at the ingredient list to see if there are added sugars (such as sucrose, sugar, and high fructose corn syrup) listed as ingredients or if there are natural sugars from foods like fruit and milk.

Complex carbohydrates usually take longer to digest than simple carbs. Just like simple carbohydrates, not all complex carbohydrates are created equal. Complex carbohydrates with fiber are typically a healthy choice. Fiber is heart healthy, good for digestion, and helps keep you full. Try to eat high-fiber complex carbs or whole grains such as whole grain breads, oats, brown rice, and bran-containing cereals instead of low-fiber complex carbs, also known as refined grains, such as white bread, white rice, white pasta, and snacks or cereals made predominantly with refined flour. Keep in mind that a product such as cereal stating “made with whole grains” or “contains whole grains” does not necessarily mean that it is healthy. It just means that at least one of the ingredients is a whole grain. Make sure to check the ingredient list to confirm that the first one or two ingredients is a whole grain.

Are carbs unhealthy?

No. Carbs are found in very nutritious foods such as fruits, vegetables, beans, whole grains, milk, and yogurt. Some people think that eating carbs will make them gain weight, but carbs, just like all other nutrients, will get stored as fat only if you eat more than your body needs. There are many other important nutrients in carbohydrate foods, so avoiding carbs altogether is not a good idea. Carbohydrates are also the preferred fuel of a very important organ – your brain! If you don’t eat enough carbohydrates, your body will have to use protein (to make up for the missing carbohydrates).

Is a low-carb diet safe and healthy?

Your body needs carbohydrates as a source of fuel (energy). If you don’t eat enough carbs, your body will use stored energy from muscle or fat cells to fuel itself. On a diet like this, you would be eating more fat and protein than usual, which may not be the healthiest way to eat long term. Low-carb diets can be high in unhealthy saturated fat (found in meat, whole milk, cheese, butter, and ice cream). Also, protein digestion uses stored calcium from the body and requires extra work by the kidneys. This is a concern especially if you are a growing teen because your bones need adequate amounts of calcium to grow and be strong. Some health care professionals are concerned about possible long-term risks of a high-protein diet/low-carb diet.

Do low-carb diets work?

A low-carb diet may help some people lose weight quickly because it limits their food choices so much that they end up eating less. Keep in mind that this weight loss happens because they’re eating less food, not because they’re avoiding carbs. Research has shown that low-carb diets are no more effective in promoting long term weight loss compared to other types of diets. Instead of avoiding carbs altogether, try reducing portion sizes and choosing high-fiber carbohydrates such as whole grains, beans, fruits, and veggies instead of refined carbs such as white bread, white rice, candy, chips, or cookies. For example, instead of a plate full of pasta try using whole wheat pasta and decrease the portion to 1/4 of the plate, filling the rest with chicken breast and a salad.

How many carbohydrates should I be eating?

How many carbohydrates a person should eat depends on their age, gender, size, and activity level so it is different for each person. In general, try to follow the MyPlate model and make half of your plate fruits and veggies, and the other half whole grains and protein. If you do this, approximately half of your day’s total calories will come from carbohydrates in the form of fruit, vegetables, grains, legumes, and dairy. Think of the sources of carbohydrate in your meal; if there are several sources of simple carbohydrates (such as the bun on a hamburger, french fries, and a soda) chances are you could decrease the portion of carbs.

What’s the difference between carbohydrates and gluten?

You’ve probably seen some advertisements for “gluten-free” foods and wondered if these are healthy and if they’re different from “low-carb” foods. Gluten is a protein found in wheat, rye, and barley (which are food forms of carbohydrate). Some people have a disease, called Celiac disease, which makes gluten harmful to their digestive system. Others have a diagnosed gluten intolerance that prevents them from digesting gluten appropriately. People with Celiac disease and those who have a diagnosis of gluten intolerance must eat gluten-free foods, but they need just as many carbohydrates in their diet as someone without the disease. They can get the carbohydrates their body needs by eating carbohydrate-rich gluten-free foods such as corn, potatoes, rice, and vegetables. Eating a product marked “gluten-free” doesn’t mean that it has any less carbohydrates or that it is any healthier than a similar product; it’s just made with ingredients that don’t come from wheat, barley, or rye.

What does “low glycemic index” mean?

Glycemic index is a number used to describe how a food affects blood sugar. Carbohydrates with a lower glycemic index cause a lower and slower rise in blood sugar. For example, high-fiber complex carbs such as whole-wheat bread have a lower glycemic index than simple carbs or refined complex carbs such as white bread. This is because the fiber in foods with complex carbs takes longer to digest and break down into sugar in the blood.

Combining carbs with a food containing protein or fat can also lower the glycemic index because it causes your body to absorb the carbohydrate more slowly. For example, if you add peanut butter (protein) to toast (carbohydrate), your blood sugar will not rise as quickly or as much as it would have if you had eaten the toast alone.