Think All Carbs and Sugar Are 'Bad'? Here’s Why Nutrition Experts Disagree!

Have you ever encountered the common advice to avoid sugar and other carbs for better health?

This advice is a prominent example of diet culture—a belief system that favors specific body types and eating habits while criticizing others, often marginalizing those who don't fit its ideals. Diet culture tends to portray carbs (and other macronutrients) as inherently harmful without question.

Dietitians have a different perspective, particularly for athletes and active individuals. Below, they address some myths and facts they believe everyone should understand.

The top myth about carbs and sugar? That they’re entirely ‘bad’ or ‘useless.’ Dietitians could talk for hours about food myths, especially around carbs and sugar. Many stem from the misconception that all carbs and sugars are "bad" or "useless" for the body.

It’s true that excessive sugar isn’t ideal. A recent BMJ review of various studies found links between dietary sugar and negative health outcomes, including diabetes, high blood pressure, heart disease, cancer, dental issues, depression, and more. Practicing intuitive eating and ensuring balanced daily meals can help prevent excessive sugar intake.

However, sugar has more value than often acknowledged.

“Sugars are essential for our bodies,” said Jessica Jaeger, a registered dietitian specializing in eating disorders, intuitive eating, and sports nutrition.

She noted that cutting out carbs can lead to issues like undernourishment, fatigue, mood swings, digestive problems, hormonal imbalances, and more.

“Carbs and sugar have been unfairly criticized for years, but in reality, it’s rare to label an entire food group or nutrient as ‘good’ or ‘bad,’” agreed Cara Harbstreet, a sports nutrition dietitian. “Nutrition is much more complex than that.”

This is especially relevant for athletes and active individuals. Sarah Schlichter, a “non-diet” sports nutrition dietitian, explained that carbohydrates are “preferred” for those who exercise. Carbs also provide essential vitamins, minerals, and fiber.

Carbs and sugar can support your workouts. Glucose, a type of sugar found in carbs, is the preferred energy source for your body and brain.

“Your brain, organs, and muscles function optimally when fueled properly, especially during intense workouts,” Harbstreet said.

“While it’s possible to use fat reserves, it’s a less efficient process that requires time and training. Simple carbohydrates (like sugar) can enhance performance and help you feel your best during exercise.”

Carbs are stored as glycogen in muscles and the liver, aiding in athletic performance. If athletes don’t consume enough carbs, their glycogen reserves can deplete, impacting their performance, Jaeger noted.

Without carbs, maintaining peak performance during workouts can become challenging.

The body can digest glucose and carbs quickly. This quick digestion offers two main benefits.

Firstly, it minimizes the risk of digestive issues during workouts, Harbstreet explained.

Secondly, it allows the body to access energy faster.

“Carbs break down into glucose, which is the fastest fuel for muscles and requires less oxygen than other energy sources, making it more efficient,” Schlichter added.

“Having more glucose available in muscles can prevent low blood sugar during workouts and support performance because the fuel is ready almost instantly, unlike fat or protein breakdown.”

Carbs and sugars assist with hydration. Yes, staying hydrated is easier with carbs and sugars. As dietitian Anna Sweeney highlighted in a social media post, “electrolytes without carbs aren’t as effective.”

“Carbohydrates attract water, helping the body absorb it,” Jaeger explained.

Carbs help water and salt enter the bloodstream, Schlichter said, and sugar intake helps balance blood sugar, which can trigger hunger and thirst, aiding in preventing dehydration.

“Combining sodium, electrolytes, fluids, and glucose is a quick way to rehydrate at the cellular level,” Harbstreet added. “This method supports fluid balance better than drinking plain water alone.”

How many carbs do you need? If you’re uncertain whether you’re consuming enough carbs and sugar to support your body and workout, consider your physical and mental state.

“You should feel focused, energized (even if slightly fatigued from exercise), and ready to recover for the next session,” Harbstreet advised. “Feeling hungry is normal, but you shouldn’t be extremely hungry or feel depleted.”

Schlichter shared signs that you might need more carbs: frequent hunger, slow recovery, feeling underperforming, low blood sugar, constant thoughts about food, waking up hungry, frequent injuries, hair loss, and missing menstrual cycles.

Jaeger emphasized that everyone’s needs vary and suggested consulting a sports dietitian for personalized advice. She also recommended consuming carbs with most meals and snacks.

What kinds of carbs are best for workouts? Food can enhance both your workout and your enjoyment of it. Dietitians recommend simple, low-fiber carbs before and during exercise to minimize digestive discomfort, and complex carbs (with protein) afterward to aid recovery.

Schlichter noted that simple carbs are commonly found in fruits, bagels, waffles, white bread, electrolyte drinks, juice, and crackers.

Complex carbs, such as beans, potatoes, corn, green peas, oats, brown rice, and quinoa, are better post-workout options. For easy consumption, Harbstreet suggested protein shakes or chocolate milk if you’re not hungry after a workout.

“There are benefits to choosing whole-food carbs or sports-specific nutrition, so don’t hesitate to experiment and find what suits you,” Harbstreet advised. “Generally, something is better than nothing.”

Ultimately, carbs and sugar are essential for everyone, not just athletes. Our bodies are continuously working, burning calories and energy, even when we aren’t aware of it.