First it was Paleo, then it was Keto. Now it’s carb cycling. With all of the ever-changing diet must-dos (and don’ts), how do we determine if any one theory is good or bad for us? In this article, I’m going to talk about carb cycling so that you can decide for yourself whether it’s a do or a don’t. If you’re struggling to lose weight, it may be worth trying to see if it works for you (bearing in mind that everyone’s body is different and responds differently to various diets).
What is carb cycling?
Carb cycling is a diet method in which you vary the amount of carbohydrates you consume each day. On low carb days, you consume approximately 0.5 grams of carbohydrate per pound of body weight. For someone who weights 150 pounds, that means about 75 grams of carbohydrates.
A low carb day for a 150-pound person might look something like this:
- Meal 1: 2-3 eggs, 1 slice of Ezekiel bread, and 1/4 of an avocado
- Meal 2: Baked chicken and non-starchy vegetables
- Meal 4: 1 oz. of almonds and 1/4 cup of blueberries
- Meal 3: Spinach salad, 1/4 cup of blueberries, 1/4 of an avocado, and lean meat dressed with oil and vinegar
- Meal 5: Low carb protein shake
On high carb (“re-feed”) days, you would consume about 2-2.5 grams of carbohydrate per pound of body weight. So a 150 pound person would consume 350-375 grams of carbohydrate. High carb days are typically the highest calorie days as well. Most carb cyclers also include zero carb day during which they consume less than 30 grams of carbohydrate.
There are a lot of ways to model high, low, and zero carb days. For example, someone may have 1-2 weeks of low carb days before having 1 high carb day. You could also have 3-4 low carb days, followed by 1 high carb day, followed by 1-2 zero carb days. The possibilities are countless. The one thing that remains the same is that typically there are more low carb days than high carb days, and the exact model should be based on your body type, goals, and training methods. Additionally, re-feeding should occur on days when you do higher intensity or higher volume workouts.
If this seems complicated, that’s because it IS complicated. Following an exact carb cycling diet takes nutritional expertise and meticulous planning.
Why carb cycling?
The health and fitness world have a serious love-hate relationship with carbs. On one hand, carbohydrates are an excellent source of energy for our muscles, especially when it comes to anabolic exercises. Carbohydrates also aid in muscle recovery. In fact, most experts recommend consuming both protein and carbohydrate (at a 1:3 ratio) within 30-45 minutes after a workout. On the other hand, carbohydrate is also associated with increased insulin, resulting in increased fat storage.
It almost seems paradoxical, but, like fat, it’s more likely that the right amount of carbohydrate is beneficial while too much carbohydrate (and not carbohydrate itself) is detrimental.
Proponents of carb cycling view it as a way to gain the benefits from carbohydrates (including replenishing glycogen stores and promoting muscle growth) while preventing fat gain, or even promoting fat loss.
Carb cycling attempts to match the body’s need for carbohydrate each day based on activity level.
Benefits of high carb days include:
- Consuming carbohydrates immediately after and for several hours after exercise replenishes glycogen stores, which means faster recovery and more energy for your next workout
- May improve function of appetite regulating hormones, leptin (reduces appetite and increases energy expenditure) and ghrelin.
Low carb days are thought to improve the body’s ability to utilize fat for fuel and may improve insulin sensitivity. (This is also the idea behind the Ketogenic diet).
Basically, carb cycling is thought to reap the muscle growth, recovery, and hormonal benefits of high carb diets and the fat burning and insulin-related benefits of low carb diets without the negative effects associated with either one.
The research on carb cycling is sparse, but here are a few summaries of what I have been able to find:
- A 2016 study looked at the effects on exercise performance after switching to a 14-day high carbohydrate diet in a low carbohydrate adapted cyclist. The study found that the switch enhanced the cyclist’s high intensity endurance performance, but negatively affected his moderate intensity performance.
- A 2001 study found that going from a standard carbohydrate diet to a high fat (low carbohydrate) diet for 6 days followed by 1 day of rest and a high carbohydrate diet resulted in better athletic performance than going from a standard carbohydrate diet to a high carbohydrate diet.
- A 2015 study of the strongest and fittest special ops operators found that the strongest and fittest consumed diets higher in carbohydrates and seafood/plant-based protein.
- A 2014 review of multiple studies concluded that exact diet should depend on a variety of factors, including type of sport, body type, and volume and intensity of training. The authors stated that a low carbohydrate diet (and carb cycling is essentially a low carbohydrate diet) is preferred for athletes who train at moderate to high intensity, or 60-75% VO2max, and that a high carbohydrate diet is preferred for athletes who train at very high intensities, or over 80% VO2max.
The bottom line
Not much is actually known about carb cycling. There are athletes and trainers who will swear by it as if it’s some sort of miracle diet, but this doesn’t mean it’s effective for everyone or even healthy for everyone. For example, some resources recommend that carb cycling be done only for short periods of time rather than over the long term due to potential negative effects.
If you’re curious about carb cycling or feel like you’ve hit a wall with your current diet, you may want to give it a go and see if it works for you. Our bodies are all different and respond differently to various diets, so it’s important to find what works for you and not what everyone says works for everyone.
If you want to try a modified version of carb cycling without the meticulous planning, you could try consuming less carbs (and getting those carbs from fruits and non-starchy vegetables) on moderate intensity or active recovery days, and consuming more carbs, including whole grains and starchy vegetables, on high intensity or high volume days.
If you currently carb cycle or have carb cycled in the past, I would love to hear about your experience in the comments!! Feel free to like and share this article if you found it interesting or helpful, and please feel free to share any other research you know of about carb cycling!