Let’s Talk Carbs
What are carbs?
Carbohydrates are one of the three macronutrients, alongside fat and protein, that are largely responsible for supplying our bodies with energy. Carbs are made up of sugar molecules, one of which is glucose—the body’s main source of fuel. Depending on your body’s energy needs at a given moment, glucose can either be used immediately or stored in your liver and muscle tissues as glycogen to be used later. Carbs are categorized as either “simple” or “complex” depending on their molecular structure, which impacts their digestion, absorption, and function in the body.
Simple carbs
Simple carbs are comprised of one or two sugar molecules, known as monosaccharides and disaccharides. Monosaccharides are single sugar molecules, including glucose, fructose, and galactose, and disaccharides are two monosaccharides grouped together to form maltose, lactose, or sucrose. The short molecular structure of simple carbs makes them easy to break down or convert to glucose for quick energy bursts, and as a result, blood sugar spikes—which, contrary to what wellness influencers may have told you, aren’t always a bad thing.
Simple carbs often consist of added sugars or refined grains, such as candy, fruit juice, white bread, and white pasta, but also include natural sugars like honey, maple syrup, and cane or coconut sugar. Of course, these foods can be part of a healthy, balanced diet, but it’s best to enjoy them in moderation as they lack substantial vitamins, minerals, and other nutrients. Nevertheless, simple carbs can be effective pre-workout fuel because of their rapid digestibility and resulting energy provision.
Complex carbs
Complex carbs contain three or more monosaccharides bonded together and are categorized as either oligosaccharides or polysaccharides. Because of their more intricate structure, complex carbs take longer to digest compared to simple carbs, providing longer-lasting energy and a more gradual effect on blood sugar.
Starch and fibre are two types of complex carbs. Starches contain a large amount of glucose molecules, so they’re best used as a sustained energy source (Slavin & Carlson, 2014). Examples of starches include potatoes, corn, wheat, and root vegetables. On the other hand, fibre is an indigestible compound derived from plants that promotes a healthy digestive system. Fibre itself can’t be broken down, but it helps with the digestion of other foods in the intestinal tract and supports bowel regularity. Examples of high-fibre foods include fruits, vegetables, oats, whole grains, and legumes.
While starch predominantly supplies energy and fibre most notably supports our digestive system, both contain essential vitamins, minerals, and other micronutrients beneficial for overall nutrition.
Carbs and body composition
Ah, the eternal debate: do carbs make you gain weight, and should they be avoided to lose weight? Short answer: no—research has shown that carb intake is not associated with weight gain, nor does it hinder weight loss efforts (Tammi et al., 2023; Bayer & Holzapfel, 2022). Long answer: the supposed association between carbs and their obstruction of weight loss or contribution to weight gain isn’t about carbs themselves, but rather how they play into your overall calorie balance. Weight gain and loss come down to the simple equation of calories in versus calories out—if you eat more calories than you burn, you gain weight; if you burn more calories than you eat, you lose weight, regardless of whether those calories come from carbs or elsewhere. Perhaps the fuel to the carb-hating fire is that carbs can be easy to overconsume—a lot of indulgent foods are carb-heavy, and simple carbs in particular aren’t overly satiating—but, like everything else, portion control is key. Beyond their contribution to overall calorie consumption, carbs aren’t to blame for weight gain, nor are they the antithesis of weight loss.
There are actually a few reasons in favour of carbs and weight management. Fibre promotes satiety, so eating carbs rich in fibre can keep you full for longer, potentially reducing total calorie intake throughout the day (Kelly et al., 2023). Carbs also provide energy, so a low-carb diet may leave you too tired to exercise or diminish exercise performance. Additionally, restricting certain foods—in this case, carbs—may leave you more likely to binge, but more on that in my post All Foods Fit: Ditching Restrictive Diets. It’s therefore best to skip the diet culture BS and instead focus on a well-balanced, carb-inclusive diet to optimize your goals and overall nutrition.
Recommended carb intake
The Acceptable Macronutrient Distribution Range (AMDR) recommends that 45-65% of total daily calories come from carbohydrates. Considering carbs have four calories per gram, this would equate to a daily carb intake of 900-1300 calories, or 225-325 grams, based on a 2000-calorie diet. These numbers will, of course, vary depending on your unique caloric needs and are largely dependent on your level of physical activity—the greater the intensity or duration of your training, the more carbs you’ll need to fuel those sessions.
Light exercise
Those participating in light exercise, such as walking or yoga, may require a daily carb intake closer to the lower end of the AMDR, or about 3-5 grams per kilogram of bodyweight per day (Dietitians of Canada, 2016).
Moderate exercise
The mid-range of the AMDR, or a carb intake of about 5-7 g/kg per day, is often appropriate for moderate exercise—running, swimming, pilates, resistance training (usually), or other activities lasting an hour or less (Dietitians of Canada, 2016). With regard to resistance training in particular, there’s little evidence to suggest that an elevated carb intake significantly affects performance or training outcomes, so a moderate carb intake is likely sufficient. That is, unless your training volume exceeds ten sets per muscle group per session, but even then, further research is needed (Henselmans et al., 2022).
Intense (endurance) exercise
The upper limit of the AMDR is best suited for endurance athletes, especially those training for more than an hour at a time. These individuals may require upward of 6 grams of carbs per kilogram of bodyweight per day, potentially up to 12 grams for extreme endurance (Dietitians of Canada, 2016).
Moderate overconsumption of carbs, particularly complex carbs, in relation to exercise likely won’t cause any harm, as long as your other macronutrient needs are also being met within your caloric requirements. Conversely, falling short of carb recommendations likely won’t lead to significant consequences if training performance or intensity aren’t overly important to you (Dietitians of Canada, 2016). It is, however, crucial that your daily carb intake is complementary to your fibre needs—there definitely are adverse effects of not enough (or too much) fibre.
Recommended fibre intake
Ensuring you’re eating enough complex carbs to meet your fibre needs is crucial to supporting overall health. As discussed, dietary fibre is necessary for a healthy digestive system and bowel regularity, but it also plays a role in the prevention of heart disease, high blood pressure, obesity, type 2 diabetes, and some cancers (Quagliani & Felt-Gunderson, 2017). The current recommendation for daily fibre intake is 25 grams for women and 38 grams for men, but North Americans typically fall short at about 17 grams per day (McManus, 2019; McKeown et al., 2022).
Generally speaking, things like fruits, vegetables, oats, whole-grain breads or cereals, and brown rice are great sources of fibre. On packaged foods, you can look at the Nutrition Facts label for fibre content or certain fibre-related phrases. In Canada specifically, claims such as “source of fibre”, “high source of fibre”, and “very high source of fibre” are government-regulated—two, four, and six grams of fibre, respectively, are required per serving to make such claims, but make sure you look at the serving size (Bureau of Nutritional Sciences, 2021).
Mindfully selecting your carbs is an effective way to augment your daily fibre needs. Also, keep in mind that simple or less fibrous carbs can still be part of a healthy, balanced diet alongside complex carbs—variety is key in nutrition.
To weigh or not to weigh?
If the thought of weighing your rice sounds soul-sucking—same. I’m not hating on macro counting if it works for you or if it’s necessary for your goals, but I personally don’t count calories or macros. I much prefer an intuitive or “eyeballing” approach to nutrition, and I truly have no concept of how many carbs I eat on a daily basis. Unlike protein, where I have a rough idea of my intake, I couldn’t even venture a guess for carbs, and I’m okay with that uncertainty. Our bodies need different things on different days, so I’ve learned how to trust my intuition and bodily cues instead of a food scale. If you don’t want to count carbs, you don’t have to—as long as you feel satisfied and energized, you’re enjoying a diverse range of complex carbs to optimize your micronutrient and fibre needs, and carbs fit within the context of your other macros, you’re probably doing just fine.
While I don’t count carbs, I am intentional with them, and I’ll usually pair carbs with protein and/or fat—ideally both. For example, if I want an apple, I’ll dip it in Greek yogurt and peanut butter; if I want crackers, I’ll throw in some cheese and deli meat; and if I want oatmeal, I’ll mix in protein powder and nuts. Combining carbs with other macros boosts the nutritional value of your meals and snacks to give you more bang for your buck, plus it’s more satiating, so you’re not hungry again in twenty minutes. I want to be clear that there’s nothing wrong with “naked carbs,” and you absolutely can and should enjoy carbs on their own from time to time. This is simply a tip I like to use to make the most of my nutrition, but sometimes you just want some damn carbs by themselves, and that’s totally okay, too.
Key takeaways
Let’s recap, shall we? Carbohydrates are the body’s main fuel source, providing us with glucose to power day-to-day activities, bodily functions, and exercise. Simple carbs offer rapid energy, while complex carbs supply sustained energy alongside vitamins, minerals, and fibre. According to the AMDR, carbs should comprise 45-65% of total daily calories, with physical activity largely determining optimal intake within this range.
Alongside carb intake comes fibre intake—males and females require 38 and 25 grams of fibre per day, respectively, and complex carbs can substantially contribute to this guideline. Nevertheless, despite their limited micronutrient and fibre profile, simple carbs can still be part of a healthy, balanced diet—everything has a time and place in nutrition.
Unless you want to, you don’t need to count or weigh your carbs. If you feel energized and satiated and you balance carbs alongside other macros, you’re likely within a healthy range. To optimize my carb intake, I usually combine carbs with protein and fat, and I incorporate a variety of complex carbs into my diet—diversity in nutrition helps you reach micronutrient needs in addition to macronutrients.
As we come to a close, I want to take a moment to simply appreciate carbs. They’re good for the mind, body, and soul—carbs energize us, satiate us, nourish us, and above all else, taste f*cking amazing. I’m tired of carbs being the villain of diet culture, so let’s rewrite that narrative and start giving carbs the long overdue respect they deserve. A round of applause for the carbohydrate—thank you for being f*cking awesome.
Below is an overview of recommended daily carb intakes by activity level, but remember that precision isn’t always crucial—do what works for you.
LIGHT EXERCISE:
3-5 g/kg/day
MODERATE EXERCISE:
5-7 g/kg/day
INTENSE ENDURANCE EXERCISE:
6-10 g/kg/day
VERY INTENSE ENDURANCE EXERCISE:
8-12 g/kg/day
References
Bayer, S. & Holzapfel, C. (2022). Carbohydrate intake - current knowledge on weight management. Clinical Nutrition and Metabolic Care, 25(4), 265-270. doi: 10.1097/MCO.0000000000000840
Bureau of Nutritional Sciences. (2017, May). Policy for Labelling and Advertising of Dietary Fibre-Containing Food Products. Government of Canada. https://www.canada.ca/en/health-canada/services/publications/food-nutrition/labelling-advertising-dietary-fibre-food-products.html
Dietitians of Canada. (2016). Nutrition and Athletic Performance. Dietitians of Canada, the Academy of Nutrition and Dietetics and the American College of Sports Medicine. https://www.dietitians.ca/DietitiansOfCanada/media/Documents/Resources/noap-position-paper.pdf?ext=.pdf
Henselmans, M., Bjørnsen, T., Hedderman, R., & Vårvik, F. T. (2022). The Effect of Carbohydrate Intake on Strength and Resistance Training Performance: A Systematic Review. Nutrients, 14(4), 856. doi: 10.3390/nu14040856
Kelly, R. K., Calhoun, J., Hanus, A., Payne-Foster, P., Stout, R., & Sherman, B. W. (2023). Increased dietary fiber is associated with weight loss among Full Plate Living program participants. Frontiers in Nutrition, 10. https://doi.org/10.3389/fnut.2023.1110748
McKeown, N. M., Fahey, G. C., Jr., Slavin, J., & van der Kamp, J.-W. (2022). Fibre intake for optimal health: how can healthcare professionals support people to reach dietary recommendations? BMJ, 378. doi: 10.1136/bmj-2020-054370
McManus, K. D. (2019, February 27). Should I be eating more fiber? Harvard Health Publishing. https://www.health.harvard.edu/blog/should-i-be-eating-more-fiber-2019022115927#:~:text=Fiber%3A%20how%20much%20is%20enough,and%2030%20daily%20grams%2C%20respectively.
Quagliani, D. & Felt-Gunderson, P. (2017). Closing America’s Fiber Intake Gap. American Journal of Lifestyle Medicine, 11(1), 80-85. doi: 10.1177/1559827615588079
Slavin, S. & Carlson, J. (2014). Carbohydrates. Advances in Nutrition, 5(6), 760-761. DOI: 10.3945/an.114.006163
Tammi, R., Männistö, S., Harald, K., Maukonen, M., Eriksson, J. G., Jousilahti, P., Koskinen, S., & Kaartinen, N. E. (2023). Different carbohydrate exposures and weight gain-results from a pooled analysis of three population-based studies. International Journal of Obesity, 47(8), 743-749. doi: 10.1038/s41366-023-01323-3