As low-carbohydrate diets have gained popularity, we have been inundated with claims that “carbs are the enemy.”
Yes, many companies add extra sugar to their products to make them taste better so we buy more, but here we aren’t just talking about added sugars.
Rather, we are talking about all carbohydrates.
A Google search for “carbs cause” shows what we tend to associate carbs with:
The next search illustrates more of our confusion surrounding carbohydrates. Are they bad, good, or “the devil”?
Many of us are more confused about carbohydrates than we even realize - often using “carbs” to refer to foods that can have nearly as many calories from fat as from carbohydrates, like pizza or French fries.
Let’s examine some of the lies we’ve been told about carbohydrates that might be causing this confusion:
1. There Are “Good” Carbs and “Bad” Carbs
While there are different types of carbohydrates, and these different types can affect us in different ways, to claim that carbohydrates can be “good” or “bad” implies that some are inherently beneficial and some are inherently harmful. This is simply not the case.
Including apples (or quinoa or kale or bread) in your diet will not make you healthy or unhealthy. Your entire dietary pattern and total caloric intake are what can be “good” or “bad” for you.
2. Carbs Make You Fat
A macronutrient cannot cause any weight gain, let alone fat gain, unless overall caloric intake is greater than overall caloric expenditure.
This means that yes, carbs, protein, and fat can each technically “make you fat,” but only if they make up excess calories that you are consuming.
3. Vegetables Don’t Count
Vegetables contain calories and consist of carbohydrates, protein, fat, vitamins, minerals, and other beneficial compounds. The confusion about vegetables may come from the fact that many of them have a high water and fiber content.
The high water content of vegetables contributes to their high nutrient density (meaning low calorie content per serving size). For example, 3 cups of raw broccoli shrink down to a smaller size after being roasted and will have a similar carbohydrate content to many popular brands of bread.
The raw broccoli is just more filling because of the high water content. Despite the high nutrient density of vegetables, they do indeed have calories, carbohydrates, protein, and even some fat. We can overeat vegetables just like we can overeat any other food.
4. Net Carb Content Is More Important Than Total Carb Content
“Net carbs” are calculated by taking the total carbohydrate content of a food and subtracting the fiber and sugar alcohols from that total. The idea is that only the remaining carbohydrates will significantly impact our blood glucose levels.
Unfortunately, many food companies will advertise “net carbs” to make it seem like their food is low-carbohydrate when in fact it is not. This can lead to many people thinking that they are consuming less carbohydrates than they are, which can hinder fat loss progress and ultimately sabotage one’s diet!
Remember that there are many types of carbohydrates that can have different short-term effects on the body, but in the end, all carbohydrates provide us with energy.
5. Fruit Has Too Much Sugar
Many think that fruit is too high in sugar – specifically fructose – to include in one’s diet. Although fructose has different metabolic effects on the body, there is no clear reason to swap fructose for glucose1.
Furthermore, there is a difference between eating pure fructose and fruit. Fruit also contains fiber, vitamins, minerals, and other beneficial compounds. A common mistake when dieting is to cut out fruit without getting enough vegetables and resort to nutrient-poor sources of carbohydrates, like rice cakes.
This can contribute to low intake of key nutrients and potentially even nutrient deficiencies. Especially when in a caloric deficit, it is crucial to ensure that one’s diet is high in nutrient-dense foods like fruit and vegetables.
6. You Don’t Need Carbohydrates
One common claim by many who advocate for low-carbohydrate diets is that carbohydrates are not necessary – not just for fueling workouts, but in general. However, carbohydrates are used during high and moderate intensity exercise2,3 and as our preferred fuel source in everyday life.
The exception to this is when individuals choose to follow a ketogenic diet, through which the body switches to ketones – a type of fat – for fuel instead of carbohydrates.
7. You Shouldn’t Eat Carbs at Night
Avoiding carbohydrates at night does little to nothing for weight loss (or weight gain) efforts. While exercise has implications for nutrient timing, there is limited impact of any meal timing on weight loss or body composition4.
However, when it comes to short-term effects, like raising insulin levels or impacting one’s sleep quality, carbohydrate timing does matter.
8. Carbs Cause Inflammation, Gas, Acne, and Bloating
The statement that carbohydrates can cause any symptom is complex because the effect of a food on the human body varies by individual. However, speaking generally, the entire class of macronutrients cannot cause a symptom.
When we talk about gas or bloating, a specific food or type of carbohydrate, like fiber, artificial sweeteners, or lactose, may be the culprit. Diagnoses like IBD and related digestive disorders can also contribute to gas and bloating.
When it comes to cause-effect relationships, there’s a lack of evidence for any of the effects mentioned here, but each of us may experience our own food sensitivities.
9. White Bread Is Worse Than Whole-Grain Bread
Generally, all types of bread have similar long-term effects on the body. Highly processed grain products, like white bread, are often fortified with vitamins and minerals, so the only notable difference is the typically higher fiber content in the less-processed grains.
This can change how the food affects our blood sugar levels, but when we compare white and whole-grain bread consumption as part of a balanced diet with overall caloric intake set for goals (e.g. a caloric deficit for weight loss), there is no notable difference.
Highly-refined types of bread can increase blood sugar levels more than less-refined types of bread, which matters for those of us with diagnoses such as diabetes.
10. Avoiding Added Sugar is Key to a Healthy Diet
There is some truth to this statement, in that adding sugar to food changes the ratio of sugar to other nutrients, making the food more energy-dense (i.e. it will have a higher calorie-to-nutrient ratio). This is what we mean when we talk about “empty calories.”
The same thing happens when we instead remove water or fiber rather than adding sugar. For example, “No Sugar Added” juice is missing some water and fiber that was part of the whole fruit, so that calorie-to-nutrient ratio (and sugar-to-nutrient ratio) changes the energy density.
Even when we juice fruit in a juicer, we lose out on fiber and change that ratio. Paying attention to the nutrient density by consuming a balanced, varied diet is what is truly key to a healthy diet.
It is important to remember that single foods and macronutrients can have short-term effects on our bodies but cannot cause any long-term harm (or benefit) on their own. The entire dietary pattern and caloric intake must be taken into account when it comes to long-term effects of diet on our bodies.
Additionally, it is important to pay attention to your own body and mind in addition to the scientific evidence. You might sleep better or worse after a high-carbohydrate bedtime meal. You may never or always experience digestive discomfort after eating a bowl of broccoli. It is the impact of diet on your body that truly matters.
Many “health food” bloggers love to post meals full of vegetables and fatty foods, like avocado, nuts, seeds, eggs, and salmon. Not just refined grains, but often whole grains, may be missing from these “healthy” meal posts. These photos are not representative of the USDA guidelines that suggest filling half our plate with fruit and vegetables and the other half with grains and protein5.
Most of our calories should come from carbohydrates, so don’t fear this misunderstood macro!
- Sievenpiper JL, de Souza RJ, Cozma AI, Chiavaroli L, Ha V, Mirrahimi A. Fructose vs. glucose and metabolism: do the metabolic differences matter? Curr Opin Lipidol. 2014;25(1):8-19.
- Costill DL. Carbohydrate for athletic training and performance. Bol Asoc Med P R. 1991;83(8):350-3.
- Mul JD, Stanford KI, Hirshman MF, Goodyear LJ. Exercise and regulation of carbohydrate metabolism. Prog Mol Biol Transl Sci. 2015;135:17-37.
- Kersick CM, Arent S, Schoenfeld BJ, Stout JR, Campbell B, Wilborn CD, Taylor L, Kalman D, Smith-Ryan AE, Kreider RB et al. International society of sports nutrition position stand: nutrient timing. J Int Soc Sports Nutr. 2017;14:33.
- U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015–2020 Dietary Guidelines for Americans. 8th Edition. December 2015. Available at http://health.gov/dietaryguidelines/2015/guidelines/