As a dedicated runner and avid weightlifter, I’ve encountered countless misconceptions surrounding carbohydrates and their role in fitness and weight management. Contrary to prevailing beliefs, I staunchly advocate for the essential role of carbohydrates in fueling performance, sustaining energy levels, and optimizing athletic endeavors. In this post, I aim to debunk common myths and shed light on the indispensable role of carbohydrates in supporting peak physical performance.
Dispelling the Myth: Do carbs lead to obesity?
Let’s address the elephant in the room: the pervasive myth that carbohydrates are the enemy of weight loss and physique goals. Time and time again, I’ve encountered individuals demonizing carbs, attributing excess body fat and weight gain solely to their consumption. However, the truth is far more nuanced. While excessive consumption of refined carbohydrates devoid of nutrients can contribute to weight gain, vilifying an entire macronutrient group is unjust and scientifically unfounded. The real culprit is total caloric intake. I want to present several scenarios to offer an alternative perspective. Both anecdotal and empirical.
I weight around 180lbs and currently, I’m around 13 percent body fat. I eat somewhere in the ballpark of 3200-3800 calories a day depending on if I’m running or not. A large portion of those comes from carbohydrates. I was just telling a client the other day that on days when I run, I probably consume more carbs in the morning than most people consume in an entire day. Bananas, running gels, gatorade, etc. Why am I not overweight?
Competitive body builders. It’s pretty clear to me that people that compete under the bright lights, probably have some of the leanest physiques in the world. Often walking on stage anywhere from 4-8 percent body fat depending on the event. If you could take a look at their diet breakdown, it’s very common that out of their 3-4k caloric intake, 60+ percent of their macro nutrients come from carbohydrates. If carbs make us obese, why are these people the exact opposite? Well one reason is they account for their total calories in vs total calories out and manipulate these numbers as they get closer to show day. Another reason is that they’re constantly emptying their glycogen stores so any carbohydrates they eat go towards refilling those instead of being stored on the body as fat.
Muscle glycogen is the bodies preferred fuel source for high effort activity. All of our muscles contain this, and it is comprised of about 1 gram of glucose to 3-4 grams of water. They bind together to allow us to store large amounts of sugar water all of our body. This an important concept to grasp as it makes up the main reason that people should stay active in their day to day. Emptying our glycogen stores is probably one of the best things we can do for fat loss. People chase weight loss instead of fat loss, and most of the time they’re just losing water in the form of muscle glycogen.
The last scenario I want to present are track athletes and long-distance endurance runners. While you can find some athletes that are low carb, the extent to which they are is unsure. If you look at the physique of runners, it becomes clear that when you’re active, carbohydrates don’t lead to obesity. You’d be hard pressed to find a track athlete with a body fat percentage over 10%. Similar to body builders, carbohydrates can make upwards of 60% of their diet and for the longer events it can be even higher. It’s very common to see those running half marathon and marathon distance taking what are called running gels. These gels are made up of pure sugar most of the time which comes out to about 20-25 grams of carbohydrates. I’m just finishing a training block with one of my clients running in the San Diego Marathon. His last 20 miler he was having a gel every 30 minutes. That comes out to about 7 gels and 175 grams of carbohydrates in a single run. He’s actually lost weight this training block, which was part of the plan.
I think the true culprit to the obesity epidemic is the rise of highly palatable food. Our brains are designed to reward us when we come across foods that check a lot of boxes. Evolutionarily speaking, it was very difficult to find food in the olden days and so when we found something good, it would’ve been important to remember where it was and be motivated to find it again. This is partly what our dopamine system is for.
The boxes highly palatable foods check are mouth feel, sweet, salty and include a combination of carbs and fat together in one perfect package. Big corporations do a lot of research into how to get their food products as addicting as possible to keep ones dopamine system cranking into overdrive. These types of foods never sent a satiety signal that we’ve had enough and before we know it, we have smashed a whole bag of chips or box of cookies.
So it’s not that carbs are inherently bad or addicting. The true answer is, it’s way more nuanced than that.
What do the data say?
Now for the empirical part. It’s important when looking at studies that try to discover which diets are best for weight/fat loss such as low carb, low fat, or keto, that we firstly look for one very important factor that the researchers control for. Calories equated. In a nutshell, this is when the researchers control portion sizes of all the foods the participants are allowed to eat and even provide preprepared meals for them in some studies. Because the main factor of whether someone will lose weight is calories in vs calories expended, this ensures that neither diet style receives an unfair advantage.
I’m going to provide links to 3 different studies for you to review if that’s your jam. I’ll summarize them below if it’s not.
- This randomized clinical trial compared the effects of a healthy low-fat diet to a healthy low-carbohydrate diet on weight loss over 12 months. The diets were designed to be low in added sugars, refined grains, and highly processed foods.
- The study found that there was no significant difference in weight loss between the two groups at 12 months. Both diets led to modest weight loss, with individual variability.
2.Comparison of Weight-Loss Diets with Different Compositions of Fat, Protein, and Carbohydrates
- This study compared four different diets varying in macronutrient composition: low-fat, average-protein; low-fat, high-protein; high-fat, average-protein; and high-fat, high-protein. Caloric intake was controlled to ensure participants were in energy balance.
- The study found that there was no significant difference in weight loss between the four diets over the 2-year period. All groups experienced modest weight loss, with no clear advantage to any specific macronutrient composition.
- This meta-analysis pooled data from randomized controlled trials comparing low-carbohydrate diets to low-fat diets on weight loss and cardiovascular risk factors.
- The meta-analysis found that both low-carbohydrate and low-fat diets were associated with significant weight loss. Low-carbohydrate diets were associated with slightly greater weight loss compared to low-fat diets in the short-term (up to 6 months), but differences were not significant in the long-term (12 months or more). Both types of diets showed improvements in cardiovascular risk factors.
Now it’s also important to not throw the baby out with the bath water and recognize the usefulness of other studies where they don’t control for calories. These studies help us understand human eating behavior, mechanisms of action, and the list goes on. However, when just looking at whether carbs make someone overweight vs another macronutrient, we have to control for calories. No if, ands, or buts about it. If carbs make people overweight, why do studies, where calories are equated, not show a significant difference between diets? You would expect to see more weight loss in the low carb groups, no?
Now that we’ve gotten that out of the way, let’s look at the usefulness of carbs.
Carbohydrates as Fuel for Performance:
As a runner and weightlifter, I understand firsthand the importance of carbohydrates as the body’s primary source of energy during high-intensity workouts. Carbohydrates are stored in the muscles and liver as glycogen, serving as a readily accessible fuel source for prolonged endurance activities such as distance running and intense weightlifting sessions. Depleting glycogen stores can lead to fatigue, diminished performance, and compromised recovery—a scenario no athlete desires.
Optimizing Carbohydrate Intake for Athletic Performance:
For individuals engaging in frequent and vigorous physical activity like me, prioritizing carbohydrate intake is paramount for sustaining energy levels and maximizing performance. The American College of Sports Medicine recommends that endurance athletes consume approximately 6 to 10 grams of carbohydrates per kilogram of body weight per day to replenish glycogen stores and support optimal performance. Incorporating a variety of complex carbohydrates from sources such as whole grains, fruits, vegetables, and legumes ensures a steady release of energy and sustained endurance throughout workouts. (1)
Carbohydrates and Recovery: Beyond fueling workouts, carbohydrates play a crucial role in post-exercise recovery and muscle glycogen replenishment. Consuming carbohydrates in conjunction with protein post-workout enhances glycogen resynthesis, accelerates muscle repair, and promotes recovery—a vital consideration for athletes aiming to optimize training adaptations and minimize the risk of injury. Incorporating carbohydrate-rich snacks or meals within the post-exercise window facilitates efficient recovery and prepares the body for subsequent training sessions.
As a passionate advocate for performance-driven nutrition, I urge fellow athletes and fitness enthusiasts to embrace carbohydrates as indispensable allies in their pursuit of excellence. Dispelling the myth that carbs make you fat, let’s instead recognize their pivotal role in fueling workouts, supporting energy levels, and facilitating post-exercise recovery. By prioritizing nutrient-dense carbohydrates as part of a balanced diet, we empower ourselves to achieve peak performance, unlock our athletic potential, and thrive in our fitness endeavors.
Lastly, glucose is the preferred fuel source of the body. On top of our muscles using it, all of our organs use especially our brain. In fact, it’s now been shown that the brain accounts for up to 80% of total glucose expenditure of the body. (2) Glucose helps us process information, both physical and mental!
You may have heard someone talk about the crash you experience after a carb heavy meal. This actually isn’t due to carbohydrates necessarily. You could experience the same thing after a low carb, high fat meal. What is really happening here is the blood is being drawn away from the brain and sent to the digestive system to help move food through its necessary processes. This can lead to one feeling tired or lethargic.
So, to all of my friends and family that are beginning a fitness journey, let’s fuel our passions, nourish our bodies, and embrace the power of carbohydrates for a stronger, fitter, and more vibrant lifestyle.
One last caveat… I am fully aware that there are athletes that use a low carb approach, and I am not saying that is not a valid approach. My understanding of the big picture is that this strategy is fine for low intensity, long duration events such as marathons, iron mans, triathlons, etc. The longer and slower the event, the more fat can be used as a slow burning fuel source, and the less necessary glucose will be. Although their bodies are still using glucose, the ratios are much different. I still don’t view this as a superior fueling strategy. When you start to get into faster and more explosive events such as 5k races, mixed martial arts, boxing, 400m, American football, etc, glucose becomes more necessary.
Thank you for reading and stay adaptive!
References:
