8 Carb Myths Debunked by Registered Dietitians
While many people limit carbs (Think: keto or low-carb diets), they’re an essential macronutrient. Cutting back on carbs too drastically can lead to low energy levels and cause you to overeat. “There are many misconceptions about carbohydrates,” says Maria Sorbara Mora, RD.
In reality, carbs don’t need to be the bad guy. When you prioritize healthy, whole-food sources of carbs like whole-grain bread, brown rice and potatoes, you feel satiated thanks to the fiber content and possibly experience fewer cravings for sweets.
Nutrition pros outline the things they wish everyone knew about carbohydrates, debunking some major myths in the process:
You’ve probably heard someone say they’re “cutting carbs” to lose weight. Maybe you’ve even said it yourself. But registered dietitians want you to know it’s not the only way to lose weight. “It’s true that keto dieters, who drastically cut carbs, experience faster weight loss initially,” says Samantha Cassetty, RD. However, this may be due to water weight loss, and you might regain the weight once you give up the strict eating style. Ultimately, “studies show overall weight loss results from keto or low-carb diets match other, less restrictive plans.”
What’s more, including carbs in weight-loss plans is often more sustainable. “Many of my clients have tried cutting carbs to lose weight, but they feel better and get more joy and satisfaction from eating when they include carbs in a healthy way,” says Cassetty. “That means mostly choosing the healthier, complex carbs and matching portion sizes to your needs.”
Another idea floating around — that carbohydrates are more easily stored as fat than the other two macronutrients, protein and fat — just isn’t true. Carbohydrates in their most broken-down form are sugar, which is extremely easy for the body to break down. “Before a cracker you eat has a chance to be swallowed, digestive enzymes in saliva have already begun the process of chemical breakdown,” says Mora. In fact, “because the molecular makeup of a carbohydrate is so easy to break down, they are needed most in the body as a primary fuel for the brain, muscles and practically every organ.”
If there are excess sugars in the body, three things can happen:
- Your body thinks it’s a waste of energy to create a storage site, so it increases its metabolic rate enough to burn them.
- They will be stored as glycogen in muscle tissue or the liver to be used for energy during exercise.
Your body will begin the process of lipogenesis or fat storage.
“The third option is the most energy-consuming, so your body will not readily choose this option unless it has to,” Mora explains. This tends to happen when you’ve eaten significantly more food than your body can put to use. The bottom line — “it’s not so easy for your body to store a carbohydrate as fat. In fact, it’s pretty hard.”
“A lot of people think of bread and pasta when they think of carbs, but [carbs] come in many forms, and some are more healthful than others,” says Cassetty. Often, when someone is “cutting carbs,” they really mean removing the aforementioned foods from their diet.
“But pulses [beans, legumes and peas], yogurt and milk, fruit, veggies and whole grains all contain varying amounts of carbohydrate,” Cassetty points out. “While it’s a good idea to limit overly processed carbs such as white bread and desserts, studies link consumption of wholesome carbs with healthier and longer lives.”
Another common reason people cut carbs when trying to lose weight is the idea they’ll become “fat adapted” and burn more fat as a result. “It’s true your body can run on a mostly-fat diet. But that doesn’t necessarily mean you’re burning more body fat,” explains Liz Wyosnick, RD.
“I want to reassure everyone the body is most often burning fat for fuel,” she says. “In gaps between meals, and during everyday activities, fat is being burned, and this process is actually more efficient if the cells have stored a little bit of fuel from carbohydrates, called glycogen.” If glucose (sugar) from carbohydrates is not available for this process, she adds, the body breaks down protein instead of fat to create it, which is inefficient. Thus, if you want to burn body fat, having at least some carbohydrates in your diet is ideal, from a physiological perspective.
“Carbs are important because they help healthy gut bacteria thrive,” says Melissa Macher, RD. You’ve probably heard about the benefits of a healthy microbiome. “Good bacteria help keep our gastrointestinal tract healthy and act as an immune barrier to harmful bacteria that can make us ill,” explains Macher. Fiber, which is found in carbohydrates, plays a key role in feeding these gut bacteria. “Carbohydrates that can help feed our microbiome include whole grains, fruits, beans and vegetables.”
Many of us prioritize eating protein around workouts to maximize muscle building. “It’s a mistake for people to focus only on protein to support their workouts or overall muscle integrity,” says Wyosnick. ”Proteins and carbohydrates work together to provide the muscle with fuel and the raw materials to rebuild and get stronger. If carbohydrates are skipped, you actually risk losing muscle mass or having poor recovery.”
In reality, it’s a good idea to consume some carbs before and after your workout (the specific timing and form ultimately depends on your goals), especially if you want to build muscle, she says. “Carbohydrates before a workout provide fast, usable energy demanded by your moving muscles and carbohydrates after provide the fuel source for muscle-rebuilding.”
If you’ve ever wondered whether you’re addicted to sugar or pasta, you’re not alone. But the idea these foods are physically addictive is nonsense, says Kerry Fannon McCarthy, RD. “There are physical, emotional and behavioral reasons we eat,” she explains. “As a society, our thinking is very all-or-nothing. We label foods as good or bad, healthy or unhealthy. We also like to rebel as humans. If we tell ourselves a particular food we like is off-limits and bad, we may not purchase it.” There’s just one problem: When we inevitably encounter these foods at events, restaurants or on takeout menus, we start to feel out of control. That leads us to assume we are “addicted” and can’t be trusted around these foods.
“This is not because of something in the food itself,” McCarthy explains. “Rather, it’s about the power we have given our thoughts about the food.” If you feel this way about carbs, McCarthy recommends looking into a process called habituation, which is often referred to in intuitive eating. Essentially: Make foods you’re hung up on available in your house, and don’t avoid them in social situations. Instead, aim to enjoy everything in moderation. “When we have these foods around, we know they’re there if we want them. That decreases the all-or-nothing thinking.”
The truth is carbs are good for your health in ways you might not expect. Long-term health outcomes in people who eat carbs are quite favorable Macher points out. “Complex carbs play an essential role in heart health and diabetes. The fiber found in carbs has a positive effect on cholesterol, and helps regulate blood sugar and energy levels throughout the day.”
Originally published July 2020, updated with additional reporting
Stick to your low-carb goals by tracking total net carbs in each food, meal and day in the MyFitnessPal app.