5 Myths About Carbs That It’s Time to Stop Believing

5 Myths About Carbs That It’s Time to Stop Believing

(Last Updated On: April 12, 2019)

Young woman deciding whether to eat healthy food or sweet cookies loaded with unhealthy carbs

Carbohydrates are one of the three macronutrients your body uses for energy. Carbs and fat are the primary sources of fuel your body uses to make ATP while protein is mainly used for other purposes, although your body can use protein as fuel under extreme conditions, like excessive calorie restriction or prolonged exercises.

Despite the fact that carbohydrates make up the bulk of the standard American diet, there are still lots of myths about these staples of the American diet – but a growing percentage of people are taking another approach. Believing that all carbohydrates are unhealthy, they’re adopting a low carbohydrate diet and some are taking it to a whole new level by eating a zero carbohydrate diet. Yes, it’s possible to survive on a zero-carb diet since your body can convert fats to ketone bodies that the brain and other organs can use as a fuel source. However, this isn’t optimal for most people. Why are they taking this extreme approach? Because they believe the myths that are circulated about carbohydrates. Let’s look at some of the most common ones.

Myth: Low-Carbohydrate Diets are Better for Weight Loss

This has become a common myth, thanks to the popularity of low-carbohydrate diets. However, a large study compared the impact of four different diets with differing macronutrient compositions on weight loss. What it found was that all of the diets they studied, regardless of macronutrient composition, led to weight loss when the calorie content was restricted. The key is that each of the diets consisted of whole food sources of macronutrients and the carbohydrates were healthy fiber-rich carbs. The results might have been different if the carbs in the study were replaced with processed carbs. Even though your body processes the various macronutrients differently, calories aren’t completely out of the picture.

Myth: All Carbs are the Same & You Should Cut Back on All of Them

Low-carb dieters try to demonize all carbs and lump them all into a single group. Don’t forget that fruits and vegetables are carbohydrates and we know that colorful produce has a variety of health benefits. It’s the processed carbs and sugar you have to watch out for. Refined carbs, including foods made with white flour, added sugar, and processed cereals, cause a rapid rise in blood sugar and don’t have enough nutritional value to justify eating them. However, fruits, vegetables, whole grains, and legumes have substantial health benefits.

In fact, many of the longest living cultures, those from the Blue Zones, eat a diet heavy in plant-based foods. To eliminate all carbs means downgrading the nutrient density of your diet. For example, leafy, greens and berries are two of the most nutrient-dense foods. If you take an extreme approach to carb restriction, berries would be off the menu. A diet rich in plant-based foods is also linked with a lower risk of heart disease, type 2 diabetes, and some types of cancer.

Myth: All Carbohydrates Cause Blood Sugar Spikes

Again, carbohydrate quality is what’s important. In fact, a 2014 study published in the Nutrition Journal showed that participants who ate a vegan, whole food diet consisting of 80% carbohydrates experienced a reduction in blood sugar as well as other “perks,” including a drop in blood pressure. Eating carbs as they’re found in nature doesn’t appear to cause unhealthy spikes in blood sugar for the average person, although insulin sensitivity varies with the individual. Some people have such low insulin sensitivity that they should limit the number of fruits high in natural sugar that they eat.

One reason fruits and vegetables don’t have a negative impact on blood sugar is the fiber and polyphenols they contain. Animal studies suggest that polyphenol-rich foods, like colorful vegetables and fruits, may improve blood sugar control via multiple mechanisms. Plus, we know that fiber helps to modify the blood glucose response to food. So, fruits and vegetables with their combination of both fiber and polyphenols should not cause blood sugar spikes for most people.

Myth: Some Forms of Sweeteners Are Better for You Than Others

We know sugar is bad – but what about other sweeteners? It’s best to avoid all sweeteners, even the ones that have a “health halo” and are perceived as natural, like agave syrup. Most commercial agave syrup is highly processed and contains more fructose than high-fructose corn syrup. It’s easy to be fooled as sugar hides under a multitude of names you might not recognize, like dextrose, dextran, and many more.

Artificial sweeteners aren’t a good fallback either. Studies suggest that these sweeteners, although calorie free, don’t turn off appetite in the same way sugar does, partially because there’s a calorie-taste mismatch. When your taste buds and brain sense something sweet going into your body, they expect calories to be delivered as well. When they aren’t, your appetite stays on. Plus, there’s concern that artificial sweeteners disrupt healthy, gut bacteria.

If you can’t give up sugar entirely or need something to sweeten your coffee, Stevia and monk fruit are two of the healthier alternatives and they don’t negatively impact blood sugar. They’re also essentially calorie free. But, make it your goal to give up all sweeteners whenever possible. It’s simply better for you.

Myth: Carbs Cause Type 2 Diabetes

Type 2 carbohydrates cause type 2 diabetes? Not directly. The biggest risk factor for type 2 diabetes is being overweight or obese. For people who aren’t overweight or obese, genetics is often a factor. Although eating the refined carbohydrates increases the risk of weight gain and may indirectly be a contributor to diabetes risk, whole food sources of carbs are actually linked with a lower risk of developing type 2 diabetes. In fact, a 2013 study showed that people who ate a diet rich in whole grains had a 25% lower risk of developing type 2 diabetes. Whole grains are a good source of fiber that slows glucose absorption from foods and helps reduce blood sugar spikes. Again, it goes back to carbohydrate quality – they aren’t all created equal. It’s the processed ones you want to avoid.

The Bottom Line

Don’t be fooled by the low carbers and zero carbers. Their dietary approach is difficult to sustain and they’re missing out on the fiber and polyphenols that are so abundant in healthy carbs. Just make sure you’re choosing the healthy ones!



Today’s Dietitian. Vol. 18 No. 4 P. 30. April 2016 Issue
Nutrition Journal .”Effects of 7 days on an ad libitum low-fat vegan diet: the McDougall Program cohort” (2014)
Nutrients. 2016 Jan; 8(1): 17. Published online 2016 Jan 5. doi: 10.3390/nu8010017.
Am J Clin Nutr November 2008. vol. 88 no. 5 1419-1437.
Eur J Epidemiol. 2013;28:845-58.


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