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Busting nutrition myths on carbohydrates

Carbohydrates have been demonized for years, but are they really as bad as everyone makes them out to be? Here’s what you need to know about carbs and the nutrition myths surrounding them.

Thanks to the rise of low-carb diets and a culture obsessed with weight loss, carbohydrates have been hailed as nutrition public enemy #1. As a result, this macronutrient has become a no-no for people wanting to shed fat, boost performance, and improve sleep habits. But is this fear of carbohydrates really warranted? We’re diving into the research to determine if carbs are as bad as everyone makes them out to be.
Carbohydrate food sources

Myth: All carbohydrates are bad for your health.

Reality: Complex carbs have multiple health benefits and can even extend your life.

First and foremost, let’s distinguish between different types of carbohydrates. Not all carbs are created equal. While some have health benefits, others can contribute to chronic disease, which is why the quality of carbohydrates you consume is just as important as the quantity [1]. There are two types of carbohydrates (simple and complex), so let’s take a closer look at them to understand the differences.

Simple carbohydrates.

Otherwise referred to as “fast acting carbs”, simple carbohydrates are broken down quickly by the body to be used as energy. While they naturally occur in dairy products and fruits (known as natural sugars), they are often added to foods in the form of refined sugars.
These refined sugars spike (and crash) your blood sugar–which can leave you feeling irritable, hungry, and tired–as well as contribute a large number of calories without adequate nutrition or feelings of fullness. Since they have little nutritional value, diets high in refined (or added) sugars can increase your risk of diabetes, obesity, heart disease, cancer, and cognitive decline [2]. 
Some dietary sources include: 
  • Fruits
  • Dairy products
  • Candy
  • Sugary beverages
  • Products with added sugars
  • Cookies
  • Breakfast cereals
  • Fruit juice concentrate

Complex carbohydrates.

Complex carbohydrates are composed of long chains of sugar molecules that take longer to digest, and hence, produce a steady supply of energy-fueling glucose that gets released more slowly over an extended period of time.
Foods that contain complex carbohydrates are often less refined than their counterparts with added, simple sugars, and provide a higher nutritional value due to the presence of vitamins, minerals, and fiber. As such, studies have found that complex carbs play a key role in digestion and regular bowel movements, cholesterol maintenance, weight management, blood sugar regulation, reduced risk of certain chronic diseases, and longevity [3,4,5]. 
Some dietary sources include:
  • Whole grains (quinoa, barley, brown rice, popcorn, and oats)
  • Legumes (lentils, chickpeas, kidney beans, green peas, and split peas)
  • Starchy vegetables (potatoes, sweet potatoes, and corn)
  • High fiber fruits (berries, avocado, guava, bananas, oranges and apples)
energy bar and banana next to cycling helmet

Myth: You shouldn’t eat carbs before exercise.

Reality: Carbohydrates are a primary source of energy and, if tolerated, should be part of your pre-workout nutrition strategy.

Whether you’re an elite athlete or recreational gym-goer, carbohydrates should be included as part of your pre-workout nutrition strategy to top off glycogen stores and provide readily-available fuel for working muscles [6,7]. 
Blood glucose and muscle glycogen (stored carbohydrates) are the most important substrates for contracting muscles in endurance activity [8,9]. Since fatigue during prolonged exercise is often associated with a depletion of muscle glycogen, research indicates that consuming carbohydrates to increase pre-exercise glycogen concentrations may be beneficial for optimal performance. This is further backed by science, as studies have found that 54% of people who ate carbohydrates prior to an hour-long workout reported enhanced prolonged performance compared to those who didn’t eat before exercise [10]. 
However, some people may feel sluggish or nauseous if they eat prior to exercise. So, if this is the case for you, it may be helpful to allow more time for your food to digest before working out. Additionally, if you have a sensitive stomach, you could try consuming higher glycemic index carbs (such as sports drinks, gels, white bread, bagels, pasta, cereals, and juice), as these are rapidly digested and absorbed. 
Here are some carb-filled nutrition suggestions to fuel your workout:
  • Protein smoothie made with milk, protein powder, banana and mixed berries
  • Whole-grain cereal and milk
  • A cup of oatmeal topped with banana and sliced almonds
  • Natural almond butter and fruit preserve sandwich on whole-grain bread
  • Greek yogurt and fruit
  • Nutrition bar with protein and wholesome ingredients
  • A piece of fruit, such as a banana, orange or apple

Myth: People with diabetes shouldn’t consume carbs.

Reality: When closely monitored, carbohydrates can be a healthful addition to any diet.

According to the Center for Disease Control (CDC), people with diabetes should aim to eat about 50% of their calories from carbohydrates [11]. While this can include any form of carbohydrates, it’s recommended to focus on consuming complex carbohydrates, as they provide fiber, vitamins, and minerals that contribute to overall health. Simple carbohydrates (or foods containing refined sugar) will spike your blood sugar and offer little to no nutritional value, so to get the most bang for your buck, consider limiting this category to make room for more nutrient-dense carb options.
Complex carbs have starch and fiber, both of which may offer benefits for those with diabetes. For instance, starch, a polysaccharide consisting of several glucose molecules connected in a chain and often found in several vegetables and whole grains, has been found to slow the release of glucose into the blood and prevent blood sugar spikes [12]. Hyperglycemia (or high blood sugar) can cause major damage over time if left unchecked (since it may lead to kidney failure, heart disease, stroke, and blindness), so by keeping blood sugar levels stable, those with diabetes can prevent any long-term consequences. 
Fiber can also increase insulin sensitivity, decrease blood pressure and cholesterol, and aid with weight loss, all of which are important for people with diabetes [13,14]. 
However, if you have diabetes, you should closely monitor blood sugar levels and regulate your carb intake based on the results. 

Myth: You can’t lose weight while eating carbs.

Reality: Complex carbohydrates are part of a healthy weight loss strategy, and can be used to maintain weight.

Complex carbohydrates are higher in fiber, which can help improve satiety and keep you fuller longer, thus aiding in appetite and weight control [15,16].
Studies show that adults who ate several servings of whole grains a day gained less weight when compared to those who rarely ate whole grains [17]. Additionally, research has found that dietary fiber intake (independent from total macronutrient and energy intake) promotes weight loss and increases the ability to stick to a calorie-restricted diet in overweight or obese adults [18].
The American Heart Association recommends a total dietary fiber intake of 25 to 30 g/day, with that range nearing 38 grams a day for men under 50 [26]. Doable, but this may be more challenging than it seems. Recent studies show that 95% of Americans don’t eat enough fiber and that the average American adult consumes just 16 grams per day [24]. Moreover, research has found that those who consume the recommended 30 g of fiber each day experience weight loss, lower blood pressure, and a better insulin response compared to people who don’t eat as much fiber [25].
Some high fiber carbs that are beneficial for weight loss (and maintenance) include:
  • Quinoa
  • Oats
  • Sweet potatoes
  • Cruciferous vegetables (broccoli, cauliflower, and brussels sprouts)
  • Legumes
  • Berries
Bunch of bananas on a blue background

Myth: Fruit has too much sugar.

Reality: Fruit contains natural sugars, which have been shown to offer multiple health benefits.

Fruit isn’t your enemy! While it’s a natural source of fructose (a simple carbohydrate), it also provides a plethora of vitamins, minerals, and fiber that contribute to overall health. 
However, like carbohydrates, not all sugar is created equal, as the effect it can have on your body depends on what type you’re eating. Here’s a brief breakdown of the difference between refined sugar and natural sugar.

Refined sugar.

This type of sugar is processed from sugar cane or sugar beets and is typically found as sucrose (a combination of glucose and fructose). Unlike naturally occurring sugars in whole foods that are typically paired with fiber and/or protein to slow digestion, refined sugars are typically not paired with fiber or protein. Hence, your body rapidly breaks down refined sugars causing insulin and blood sugar levels to spike. Additionally, refined sugars (found in processed foods, sodas, fruit juices, pastries, candy, and more) contribute a large number of calories but have little nutritional value otherwise [19]. Diets high in refined (or added) sugars can increase your risk of diabetes, obesity, heart disease, cancer, and cognitive decline [20]. 

Natural sugar.

As the name suggests, these sugars occur naturally in fruit (fructose), vegetables, grains, and dairy products (lactose). Thanks to the fiber and protein present in these foods, the natural sugars are digested and absorbed into the bloodstream at a slower rate, thus providing a steady supply of energy to your cells and a more balanced blood sugar response. They also contain other essential nutrients–like vitamins, minerals, and antioxidants–that are needed for energy metabolism, immune function, cell health, and more. 
A diet rich in fruits and vegetables can help reduce the risk of chronic diseases, such as diabetes, heart disease, and some cancers. 

Myth: Athletes should avoid carbs.

Reality: Carbohydrates are an essential nutrient for any type of athlete. 

Carbohydrates are the most efficient macronutrient group for working muscles because they provide quick, usable energy and help load and replenish muscle glycogen stores [21]. As such, athletes should include them as part of their pre- and post-workout nutrition strategy
Carbohydrates are classified as either high-glycemic (rapidly digested and absorbed) or low glycemic (slowly digested and absorbed), and both can be helpful in an athlete’s diet depending on the situation.
While high fiber, low glycemic carbohydrates offer more health benefits than refined, high glycemic carbohydrate choices, the latter may be beneficial closer to exercise–especially for those with sensitive stomachs. For instance, high glycemic carbohydrates (such as sports drinks, juice, and gels) can be useful immediately before, during, and after exercise to minimize GI distress, speed up recovery and provide quick energy [22,23]. 
Some good carbohydrate-rich foods for athletes include: 
  • Whole grains (rolled oats, rice, farro, barley, quinoa, sprouted grain bread, granola) 
  • Starchy vegetables (sweet potato, potato, squash) 
  • Fruit
  • Dried fruit
  • Nutrition bar with >25g carb and <5g fiber per serving
  • Higher glycemic refined grains (white bread, bagels, pasta, cereals, and juice)

Summary

Carbohydrates have been demonized for years thanks to the rise of low-carb diets and a culture obsessed with weight loss. While this macronutrient has been public enemy #1, it doesn’t have to be. Complex carbohydrates (such as whole grains, vegetables and legumes) are filled with vitamins, minerals, and fiber–all of which have been shown to reduce the risk of chronic disease, help with weight loss, stabilize blood sugar levels, and replenish muscle glycogen stores. However, not all carbs are created equal, so it’s recommended to limit simple carbs (in the form of refined sugars) and focus on consuming a variety of complex carbohydrates.
Disclaimer: The text, images, videos, and other media on this page are provided for informational purposes only and are not intended to treat, diagnose or replace personalized medical care. 

Key takeaways

  • Studies have found that complex carbs play a key role in digestion and regular bowel movements, cholesterol maintenance, weight management, blood sugar regulation, and longevity [3,4,5]. 
  • Carbohydrates should be included as part of your pre-workout nutrition strategy to top off glycogen stores and provide readily-available fuel for working muscles [6,7]. 
  • The starch and fiber in complex carbs can increase insulin sensitivity, decrease blood pressure and cholesterol, and aid with weight loss, all of which are important for people with diabetes [13,14]. 
  • Fruit contains natural sugars and other essential nutrients–like vitamins, minerals, and antioxidants–that are needed for energy metabolism, immune function, cell health, and more.
  • Research has found that dietary fiber intake promotes weight loss and increases the ability to stick to a calorie-restricted diet in overweight or obese adults [18].

References:

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  2. L;, P. (n.d.). The sweet danger of added sugars. European journal of paediatric dentistry. Retrieved May 12, 2022, from https://pubmed.ncbi.nlm.nih.gov/31246081/ 
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