Low-Carb Diet

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

Carbs, short for carbohydrates, 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 also found naturally in some nutritious foods like fruits and milk. Added sugars are often found in foods that have less nutritional value. Foods with high amounts of added sugars include: non-diet soda, cookies, candy, and sugary cereal (or cereal with more than 8 grams of sugar per serving). The nutrition facts label typically does not distinguish between added and natural sugars. However, as of winter 2015, the Food and Drug Administration (FDA) has proposed putting an “added sugar” line on all nutrition labels. As for now, you can look at the ingredient list to see if sugars (such as sucrose, sugar, and high fructose corn syrup) are being added to the food or if it comes from an ingredient such as fruit.

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, brown rice, and bran-containing cereals (such as Fiber One® or All Bran®) instead of low-fiber complex carbs, also known as refined grains, such as white bread, white rice, white pasta, and sugary cereal.

Are carbs unhealthy?

No. Carbs are found in very nutritious foods such as fruits, vegetables, beans, whole grains, and milk. 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 too many of them. Many other important nutrients come from carbohydrate foods, so eating no carbs is not a good idea. Carbohydrates are also the preferred fuel of a very important organ – your brain! If you don’t take in 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. In low-carb diets, only 15% to 20% of energy (calories) comes from carbohydrates. This means that the other 75% to 80% of energy must come from proteins and fats. 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, digesting protein uses stored calcium from the body and requires extra work by the kidneys. This is especially important if you are an adolescent and growing as your bones need adequate amounts of calcium to form properly 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 most of the time.

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. Other individuals have a diagnosed gluten intolerance that prevents them from digesting gluten appropriately. People with Celiac disease and those who have a diagnosed gluten intolerance must eat gluten-free foods, but they need just as many much carbohydrates in their diet as someone without the disease. They can get the carbohydrates their body needs by eating carbohydrate-rich foods such as corn, potatoes, rice, and vegetables. Eating a product marked “gluten-free” doesn’t mean that it has any less carbohydrate or is any healthier than a similar product; it’s just made with ingredients that don’t come from wheat.

What does “low glycemic index” mean?

Glycemic index is a number used to describe how a food affects blood sugar-the higher a food raises blood sugar, the higher the glycemic index. 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.

Combining a carbohydrate food with another food can also lower the glycemic index because it allows your body to absorb the carbohydrate more slowly. For example, if you add peanut butter (protein) to toast (carbohydrate), your blood sugar will increase more gradually than if you had eaten the toast alone.

What is the healthiest way to eat?

A healthy eating plan should include:

  • A variety of foods including carbohydrates, proteins, and fats
  • More high-fiber carbs and whole grains (vegetables, whole grain bread, beans, and fruits) than sugars or refined grains (candy, soda, chips, and juice)

In addition to a healthy eating plan, it’s important to engage in physical activity such as running, swimming, dancing, yoga, soccer, basketball, tennis, or other activities that you enjoy. A balance of good nutrition and fitness help maintain a healthy weight.

With all the hype about low-carb diets, it’s hard to know what to believe. Remember, carbs are healthy and needed by the body. Instead of avoiding carbs all together, think about replacing carbohydrate foods that have lower nutritional value such as cookies, chips, and fries with carbohydrates that are rich in vitamins and minerals such as vegetables, fruits, whole-grain breads and cereals, and dairy foods.