Carb cycling is a strategy that modifies carbohydrate consumption over specific periods. It’s believed to aid in fat loss and sustain athletic prowess, especially when pursuing weight reduction objectives.
The debate over carbohydrates has been burning strong for years.
Numerous popular diets limit carb amounts, with some even eliminating them altogether.
However, it’s essential to understand that no single macronutrient, including carbs, is inherently harmful. It’s all about personalizing your carbohydrate consumption to your needs.
To fine-tune their daily carbohydrate doses, many individuals have adopted a method of alternating their carb levels.
This practice is termed carb cycling.
Dive in and uncover the science and nuances behind carb cycling.
In this article
What is carb cycling?
Carb cycling is a dietary approach in which you alternate carb intake daily, weekly, or monthly.
People may use it to lose fat, maintain physical performance while dieting, or overcome a weight loss plateau.
Some people adjust their carb intake from day to day, while others may do longer periods of low, moderate, and high carb intake.
In short, carb cycling aims to time carbohydrate intake to when it provides maximum benefit and exclude carbs when not needed.
You can program your carb intake based on a variety of factors, such as:
- Body composition goals: Some people will reduce carbs during a diet and add them back during a “muscle building” or performance phase.
- Training and rest days: One popular approach is a higher carb intake on training days and a lower carb intake on rest days.
- Scheduled refeeds: Another popular approach is to do 1 day or several days at a very high carb intake as a “refeed” during a prolonged diet.
- Special events or competitions: Athletes will often “carb load” before an event, and many physique competitors will do the same before a bodybuilding show or photoshoot.
- Type of training: Individuals will tailor carb intake depending on the intensity and duration of a particular training session. The longer or more intense the training, the more carbs they consume, and vice versa.
- Body fat levels: Many individuals will cycle their carbohydrates based on their level of body fat. The leaner they become, the more high-carb days or blocks they include.
A typical weekly carb cycling diet may include 2 high-carb days, 2 moderate-carb days, and 3 low-carb days.
Protein intake is usually similar from day to day, whereas fat intake varies based on carb intake.
A high-carb day usually means low fat, whereas low-carb days are high fat.
Carb cycling is an advanced diet strategy requiring more manipulation and programming than a typical diet. To get it right, it’s helpful to consult a registered dietitian.
Summary: Carb cycling is a dietary approach in which you manipulate your carb intake depending on various factors.
The science behind carb cycling
Carb cycling is a relatively new dietary approach.
The science is primarily based on the biological mechanisms behind carbohydrate manipulation.
Few controlled studies have directly investigated carb cycling diets.
Carb cycling attempts to match your body’s need for calories or glucose. For example, it provides carbohydrates during your workout or intense training days.
The high-carb days also help your body replenish its supply of muscle glycogen, which may improve performance and reduce muscle breakdown.
Strategic high-carb periods may also improve the function of the weight- and appetite-regulating hormones leptin and ghrelin.
The low-carb days reportedly switch your body to a predominantly fat-based energy system, which may improve metabolic flexibility and your body’s ability to burn fat as fuel in the long term.
Another significant component of carb cycling is the manipulation of insulin.
The low-carb days and targeting of carbs around workouts may improve insulin sensitivity, a vital marker of health.
Suggested read: Does weightlifting help women lose weight?
In theory, this approach may support the benefits that carbohydrates provide.
Although the mechanisms behind carb cycling support its use, it’s still advisable to be cautious about this approach because of the lack of direct research. Many more clinical studies with human participants are needed to determine whether carb cycling is safe and effective.
Summary: The proposed mechanism of carb cycling is to maximize the benefits of carbohydrates and teach your body to burn fat as fuel. While this makes sense in theory, more direct research is needed.
Can carb cycling help you lose weight?
The mechanisms behind carb cycling suggest that it can benefit weight loss.
In theory, carb cycling may help you maintain physical performance while encouraging your body to burn fat for energy.
As with any diet, the primary mechanism behind weight loss is a calorie deficit, meaning you eat less than your body burns over a prolonged period.
You will likely lose weight if you implement a carb cycling diet alongside a calorie deficit.
However, the complex nature of carb cycling may confuse and make it difficult for beginners to stick to the plan.
In contrast, many people may enjoy the flexibility of carb cycling. This could probably improve adherence and long-term success for some people.
Summary: Carb cycling may help you lose weight if you maintain a calorie deficit.
Carb cycling for muscle growth and sports performance
Many people believe carb cycling can benefit muscle gain and physical performance.
Regular high-carb periods and targeted carb intake may help improve performance.
Consuming carbs during workouts may also aid in recovery, nutrient delivery, and replenishment of glycogen.
This may promote muscle growth. However, some research suggests carbs are not necessary to build muscle if protein intake is sufficient.
While these mechanisms make sense in theory, direct research comparing carb cycling to other diets is needed to provide an evidence-based answer.
Suggested read: The ketogenic diet: A detailed beginner's guide to keto
In addition, not all research supports the idea that “carb loading” improves athletic performance or muscle growth.
Overall, there isn’t enough data to know for sure.
Summary: The mechanisms behind carb cycling suggest it can help you optimize performance. However, further research is required.
Does carb cycling have any other benefits?
As mentioned earlier, carb cycling has the potential to provide some benefits.
By having periods of both low and high-carb consumption, you may get many of the benefits of both diets, as well as the potential negatives.
Benefits of low-carb periods may include improved insulin sensitivity, increased fat burning, improved cholesterol levels, and enhanced metabolic health.
High-carb refeeds may positively affect hormones during a diet, including thyroid hormones, testosterone, and leptin. High-carb periods could also reduce inflammation and help your body use iron.
These factors may play an essential role in long-term dieting success since hormones play a crucial role in hunger, metabolism, and exercise performance.
There may also be downsides to carb cycling. For starters, a complex diet can be hard to maintain. It’s also unclear whether any potential benefits will be long-lasting. Plus, there isn’t enough evidence to know whether carb cycling is safe for your health over time.
Summary: Low carb periods may provide several health benefits, and high carb refeeds can have positive effects on your hormones. The long-term effects of carb cycling are not known.
How to do carb cycling
Carb cycling has many variations, including daily alterations or more extended periods of high and low-carb intake.
Here is a sample week in which you regulate your carb intake daily:
Monday
- Exercise: weight training
- Carb intake: high
- Fat intake: low
- Amount of carbs: 200 g
Tuesday
- Exercise: aerobic exercise
- Carb intake: moderate
- Fat intake: moderate
- Amount of carbs: 100 g
Wednesday
- Exercise: rest day
- Carb intake: low
- Fat intake: high
- Amount of carbs: 30 g
Thursday
- Exercise: weight training
- Carb intake: high
- Fat intake: low
- Amount of carbs: 200 g
Friday
- Exercise: weight training
- Carb intake: high
- Fat intake: low
- Amount of carbs: 200 g
Saturday
- Exercise: rest day
- Carb intake: low
- Fat intake: high
- Amount of carbs: 30 g
Sunday
- Exercise: rest day
- Carb intake: low
- Fat intake: high
- Amount of carbs: 30 g
Even more so than a typical diet, carb cycling can take a lot of fine-tuning and adjustment along the way.
Suggested read: Post-workout nutrition: What to eat after a workout
You can experiment with the number of high-carb days per week and the number of grams of carbs per day to find the best approach for your lifestyle, exercise routine, and goals.
If you prefer a low-carb diet, you can occasionally add carb cycling as a refeed.
You can either refeed every couple of weeks or do long periods, such as a 4-week low-carb phase with a 1-week refeed.
You will also notice that the number of carbs per day can vary drastically — this depends on activity level, muscle mass, and carbohydrate tolerance.
An athlete who trains 3 hours a day or a 250-pound bodybuilder may need the upper limit (or even more), whereas an individual with a more moderate fitness level may need to refeed on only 150–200 grams.
These examples are only suggestions. There is no proven formula or ratio for carb cycling. The best option is to consult a registered dietitian to make a plan that’s tailored for you. Some dietitians specialize in making diet plans for athletes.
If you take any medications or have any health conditions, it’s essential to talk with your doctor before making significant changes to your diet. Carb cycling may not be appropriate for people with diabetes.
Summary: There are several options for carb cycling, ranging from daily changes to monthly refeeds. Consult a registered dietitian to determine what works best for you and your goals.
Example carb cycling menu
Here are three sample meal plans for low, moderate, and high-carb days. Remember that the total carbs per meal in these samples are estimates, not exact numbers. Consider working with a dietitian to develop a more precise plan that meets your particular needs.
High carb day
- Breakfast: 3 boiled eggs, 3 slices Ezekiel (or 7-seed/grain) bread, tomatoes, mushrooms, and a side of mixed fruit (60 grams of carbs)
- Lunch: 6-ounce (oz.) sweet potato, 6 oz. lean meat or fish, mixed vegetables (45 grams of carbs)
- Pre-workout: 1 serving oatmeal, almond milk, 1 cup berries, 1 scoop whey protein (50 grams of carbs)
- Dinner: 1 serving brown rice, 6 oz. lean chicken, homemade tomato sauce, 1 serving of kidney beans, mixed vegetables (70 grams of carbs)
Moderate carb day
- Breakfast: high protein yogurt, 1 cup mixed berries, stevia, 1 spoon seed mix (25 grams of carbs)
- Lunch: 6 oz. chicken salad with 4 oz. diced potatoes (25 grams of carbs)
- Pre-workout: 1 banana and whey protein shake (30 grams of carbs)
- Dinner: 1 serving sweet potato fries, 6 oz. lean beef, homemade tomato sauce, 1 serving of kidney beans, mixed vegetables (40 grams of carbs)
Low carb day
- Breakfast: 3 eggs with 3 slices bacon and mixed vegetables (10 grams of carbs)
- Lunch: 6 oz. salmon salad with 1 spoon of olive oil (10 grams of carbs)
- Snack: 1 oz. mixed nuts with 1 serving of turkey slices (10 grams of carbs)
- Dinner: 6 oz. steak, 1/2 avocado, mixed vegetables (16 grams of carbs)
Recommended carbohydrate food sources
Some carbs should be enjoyed in moderation, including simple sugars and refined carbs found in foods such as cakes, desserts, highly processed snack foods, and baked goods.
In contrast, plenty of healthy carb sources are tasty and packed full of beneficial fiber, vitamins, and minerals.
When planning your high-carb days, focus on these healthier carb choices.
Recommended carbs
Instead of labeling carbs as “good” or “bad,” consider choosing unrefined carbs whenever possible. These include:
- Whole grains: Unmodified grains are perfectly healthy and may have many health benefits. Examples include brown rice, oats, and quinoa.
- Vegetables: Every vegetable has different vitamin and mineral content. Eat a variety of colors to get a good balance.
- Whole fruits: As with vegetables, every fruit is unique, especially berries, which have high antioxidant content and low glycemic load.
- Legumes: These are a great choice of slow-digesting carbohydrates full of fiber and minerals.
- Tubers: This category includes potatoes and sweet potatoes.
Summary: Limit refined carbs and added sugars. Instead, eat primarily whole foods that contain plenty of fiber.
Summary
Carb cycling can be an effective strategy for those keen on enhancing their diet, athletic prowess, and overall well-being.
Studies have shed light on the potential benefits of carb cycling, although results can be varied. Notably, no extensive research has been conducted into the effects of a prolonged carb cycling regimen in humans.
Instead of consistently sticking to a high or low-carb intake, a balanced approach might offer physical and mental advantages.
When aiming for fat reduction through carb cycling, consuming enough protein and ensuring a caloric deficit is vital.
For personalized guidance on carb cycling and determining the right carb intake, consulting a nutrition expert can be helpful. Moreover, if you’re on medication or manage health conditions like diabetes, a discussion with your physician before adjusting your diet is crucial.
