Carbohydrates Guide: Everything You Need to Know

People trying to lose weight often debate the role of carbohydrates. Since individual carbohydrate needs vary, we've created a guide to help you optimize your carb intake and make healthier choices, whether you're aiming to lose weight, train for your first half-marathon, or something in between.

CARBOHYDRATE BASICS

Carbohydrates are found in almost all foods and provide 4 calories per gram. However, not all carbohydrates are the same. Different carbohydrates impact your body in different ways. Foods containing carbohydrates generally have a combination of two types: simple and complex.

SIMPLE CARBOHYDRATES

Simple carbohydrates are also called “sugar.” They are made of up to two sugar building blocks linked together in a chain. These building blocks can be glucose, fructose, and galactose. Because the chains are short, they break down easily, which is why they taste sweet. They are also quickly digested and absorbed into your bloodstream.

Foods that are high in simple carbohydrates include sweeteners such as table sugar, syrup, honey, candy, jellies and jams, and refined flour. Fruits, vegetables, beans, and dairy products also contain simple carbohydrates. However, these foods are also rich in vitamins, minerals, fiber, and/or protein, making them healthy choices.

COMPLEX CARBOHYDRATES

Complex carbohydrates can be either “starch” or “fiber.” These carbohydrates are made up of three or more sugars linked together in a chain. They also contain fiber and are often found in foods that also contain protein and/or healthy fats, as well as vitamins and minerals. They use the same sugar building blocks as simple carbs, but the chains are longer and take more time to break down, which explains why they don't taste as sweet. The longer chains also slow down digestion and absorption of the monosaccharides that all carbs are broken down into, leading to a more gradual insulin response and increased satiety. Foods high in complex carbohydrates include bread, rice, pasta, beans, whole grains, and vegetables.

Fiber is a type of carbohydrate, but it doesn't contribute significantly to calories because it cannot be broken down and absorbed by the body. When you look at a nutrition label, you'll see “dietary fiber” and “sugar” listed under “total carbohydrates,” but the grams never add up. This is because “total carbohydrates” includes all types of carbohydrates: sugar, fiber, and starch. Sugar and fiber are highlighted on the nutrition label because they are important. However, starch is not, so if you want to calculate how much starch a food contains, you have to use the following formula:

Total starch (grams) = Total carbohydrate (g) – dietary fiber (g) – sugar (g)

NET CARBS

Net carbs are the carbs in food that potentially raise blood sugar levels. This concept is based on the idea that insoluble fiber and sugar alcohols, not digested by the body, shouldn't be included in total carbohydrate intake. The concept became popular with keto and the Atkins Diet. To calculate net carbs, subtract fiber and sugar alcohol grams from total carbohydrate grams.

Net Carbs = total carbohydrate (g) – dietary fiber (g) – sugar alcohols (g)

It's important to note that “net carbs” lacks scientific definition and isn't regulated by the FDA on food labels. Some fibers and sugar alcohols, particularly those added to processed foods, can be partially digested and impact blood sugar levels. Prioritize whole foods when tracking net carbs. Most countries outside the United States already calculate net carbs as their standard practice by not including fiber or sugar alcohols in carbohydrate totals. Consult your doctor if you're tracking net carbs to manage blood sugar.

CHOOSING THE RIGHT CARBS

When selecting carbohydrates for consumption, prioritize nutrient-rich options. Here are three guidelines for making informed choices. Note: If you are a high-performance athlete seeking to optimize performance, these carb rules may not all apply. Consult this alternative resource.

Vegetables, beans, nuts, seeds, 100% whole-grain breads, pasta, and brown rice should be included in this rule. These foods provide fiber, vitamins, minerals, and protein.

Foods such as white rice, white bread, and conventional pasta are more processed and have lost healthy nutrients, particularly fiber.

Most sources of simple carbohydrates are considered “empty calories” because they are high in calories but lack significant micronutrients. They are a common contributor to blood sugar spikes. Fruit and milk are exceptions to this rule due to their beneficial vitamins and minerals.

TARGET CARBOHYDRATE NEEDS

Our bodies need carbs, especially glucose, to function properly. Glucose is the preferred fuel for tissues and organs, and it's the only fuel for red blood cells. If we don't get enough carbohydrates, our bodies break down protein from muscles and organs to create glucose.

The Recommended Dietary Allowance (RDA) for carbohydrates is 130 grams per day. This is the minimum amount needed to fuel an adult's brain, red blood cells, and central nervous system. Without enough carbohydrates to keep blood sugar levels stable, the body starts breaking down protein into glucose to bring blood sugar back to normal.

The RDA of 130 grams of carbohydrates per day is a minimum for adults. Most people need more. The Dietary Guidelines for Americans suggests that carbohydrates should make up 45-65% of our total daily calories. This is a wide range because everyone's body is different, and there's no one-size-fits-all answer for how many carbs to eat.

We sets carbohydrate goals at 50% of your total calories, but you can adjust these goals based on your individual needs.

To figure out how many grams of carbohydrates you need:

If you are uncertain about the most suitable percentage, explore ways to optimize your macronutrient ranges, or follow this general guideline:

For weight loss, begin by limiting your carbohydrate intake to 45–50% of your calories. If you engage in vigorous exercise for over an hour daily or train for endurance events like marathons, you might benefit from a range of 55–65%.

ESSENTIAL INFORMATION ABOUT LOW-CARB DIETS

A traditional “low-carb” diet has 40% or less of its calories coming from carbohydrates. Many people have successfully lost weight and kept it off using this approach, making it quite popular. However, it's not the only way to lose weight, and it might not be suitable for everyone.

Eating a low-carb diet, especially a restrictive one, affects your blood sugar levels, which can lead to uncomfortable side effects for some people. These may include mild to severe shakiness, nervousness or anxiety, chills, irritability, lightheadedness, headaches, hunger, nausea, fatigue, blurred vision, lack of coordination, and more. These effects, along with the required restrictions, can make a low-carb diet challenging to maintain.

If you decide to try reducing your carb intake, here are seven tips to make the transition easier:

It can be difficult to predict your reaction to low blood sugar as it varies from person to person. When starting a low-carb diet, pay attention to the signs and symptoms of low blood sugar (mentioned earlier). If you experience them, consume a small serving of a carbohydrate-rich snack, such as a piece of fruit, some crackers, or a slice of bread.

Use the app to track your food intake for at least a week to gain a clear understanding of your daily carbohydrate consumption. Gradually decrease your carbohydrate goal by 5–10% (or about 30–50 grams daily) each week until you reach your target. Remember to adjust your fat and protein goals to compensate for the reduced carbohydrates in your diet.

Registered dietitian Stepanie Nelson says that tracking net carbs is most beneficial for those following a low-carb diet. It increases food flexibility and makes it easier to reach fiber goals without exceeding carb limits. Fiber is crucial for cardiovascular health, digestive health and feelings of fullness. Tracking net carbs can also help manage blood sugar levels by identifying foods that significantly impact them.

Focus on consuming high-quality carbohydrates like whole grains, fruits and vegetables, rich in fiber, vitamins and minerals. Include high-quality proteins such as eggs, legumes, chicken, tofu, and lean cuts of beef and pork. Choose healthy fats from foods containing monounsaturated and polyunsaturated fats like fish, nuts, avocados and olive oil.

When reducing carbs, you'll likely consume (and digest) more protein. Adequate water intake is essential for optimal protein breakdown and utilization. Here are 20 ways to increase your water intake.

If you lose more than 2 pounds per week, be cautious as you might be losing more water weight and lean muscle than fat. Increase your calorie intake to achieve a slower but more effective fat-loss rate.

Be honest with yourself: Are you content with a low-carb diet? Are you feeling good? Our bodies can adapt to different carbohydrate intake, but some people struggle with constant carbohydrate cravings and blood sugar issues. If you feel like your diet is too low in carbohydrates, don't hesitate to add some back. Drastically cutting carbs isn't the only way to lose weight and isn't right for everyone. Keep this in mind, because you're more likely to achieve your goals, lose weight and keep it off if you feel good and are happy with your dietary choices.