Carb cycling and a calorie deficit are two diet strategies based on different principles. Each has unique advantages and disadvantages. As a dietitian, I will help you understand when each strategy is most effective and how to implement them.
- Carb cycling involves lowering your carb intake on heavier training days and increasing it on lighter training days to maximize performance and encourage fat loss.
- A calorie deficit involves consuming fewer calories than the body needs to maintain weight, resulting in weight loss. Depending on how it’s executed, a calorie deficit could lead to muscle and fat loss or simply fat loss.
- A calorie deficit with or without carb cycling can help you lose weight. However, carb cycling without a calorie deficit will not result in weight loss.
Carb Cycling: Overview
Carb cycling is a diet strategy where you can adjust your carbs on different days or weeks according to your training needs.
The mechanism behind the carb cycling approach is to fuel the body with its preferred fuel source based on your activity level. It is believed that cycling your carb intake, based on your training, will improve performance and body composition.
Some research supports these theories; however, there isn’t enough research to form a solid conclusion.
Carb cycling is mainly used for weight loss (by pairing it with a calorie deficit), but some use this approach to build lean muscle and minimize fat gain.
There are many ways to do carb cycling, but the best way is to find what best suits one’s nutrition and fitness goals.
How Does Carb Cycling Work?
Carb cycling involves alternating between high and low-carb days based on your workout intensity. Your calorie and protein intakes stay the same across high and low-carb days, with your carbs and fats having an inverse relationship (when carbs are high, fats are low, and vice versa).
On intense training days (e.g., leg day), when the body needs more energy from carbs and stored glycogen to perform and recover, carbs will be high (and fats will be low).
For example, your carb intake could be 55-60% of total calories, and your fat intake could be 20% of total calories.
Carbs will be low-to-moderate on rest days or less intense training days (e.g., light upper body days) when the body needs less energy.
For example, your carb intake could be 20% of total calories, and your fat intake could be 55-60% of total calories.
Pros of Carb Cycling
The benefits of carb cycling include:
- Enhanced Performance: timing high-carb days with heavier training days might help replenish muscle glycogen stores and provide the body with its preferred energy source, potentially speeding up recovery and enhancing performance during more intense workouts.
- Increased Versatility: Carb cycling is versatile because you can adjust your carb intake daily or weekly or alternate low-carb periods with high-carb ” refeeds” until you find the strategy that fits your goals and lifestyle.
- Improved Body Composition: if you have reached a weight loss plateau, carb cycling might help to overcome this by preventing your body from adapting to a consistent calorie or carbohydrate intake, potentially leading to continued weight loss progress.
- Improved Metabolic Health: Low-carb periods are linked to improvements in body composition, fat distribution, fasting glucose (blood sugars in a fasting state), and insulin sensitivity (how quickly your body responds to insulin to lower blood sugars).
Cons of Carb Cycling
The drawbacks of carb cycling include:
- Low Energy Levels: you might feel lethargic on low-carb days because you will have less energy from carb stores, impacting your ability to carry out daily activities.
- Increased Complexity: Changing your carb and fat macros daily or every few days can be challenging, especially for beginners who are new to tracking their intake.
- Time-Consuming: if you have a busy lifestyle, this diet might not be suitable for you because it requires you to plan, meal prep, and track your macros accurately. Carb cycling is time-consuming, even more so when macros change from one day to the next.
Calorie Deficit: Overview
A calorie deficit approach is for those who want to lose weight; it involves consuming fewer calories than the body needs to maintain a stable weight.
A calorie deficit is achieved by eating below your maintenance calories or increasing your energy expenditure through exercise (or both).
For example, if your maintenance calories are 3000 calories daily, consuming anything less than 3000 calories or burning more than 3000 calories will put you in a calorie deficit.
While a calorie deficit requires tracking your calorie intake, you can also track your macronutrient intake (carbs, protein, and fats) to encourage muscle preservation and improved performance (but this isn’t necessary for weight loss).
How Does A Calorie Deficit Work?
A calorie deficit allows you to lose weight because when you eat fewer calories than your body needs to maintain weight, your body uses its resources for fuel by burning fat (and sometimes muscle).
Eating less than your maintenance will result in weight loss, but the size of your deficit is crucial because it determines your rate of loss.
Losing weight too quickly can cause you to lose muscle and have very low energy levels, making it more challenging to adhere to a diet.
An appropriate calorie deficit for muscle retention and adherence is 250-500 calories daily, allowing you to lose 5–10% of your baseline weight over three months.
For example, if your maintenance calories are 2300, an appropriate deficit would be 1800-2050 calories daily.
However, if weight loss slows down or plateaus, adjustments in diet or activity are required to continue progressing.
Pros of Calorie Deficit
The potential benefits of a calorie deficit include:
- Improved Health Markers: with a calorie deficit, you can achieve a healthier weight, improve your blood sugars, lower your blood pressure, and improve blood cholesterol profiles, reducing the risk factors linked to chronic diseases (e.g., diabetes and cardiovascular diseases).
- Body Fat Reduction: a calorie deficit paired with resistance training encourages fat loss (and muscle retention), helping you reduce your body fat percentage and transform your physique.
- Food Awareness: adhering to a calorie deficit requires you to become more aware of your food choices, portions, and calorie content.
- Easy To Follow: implementing a calorie deficit is very straightforward because you must meet your calorie target, whereas other nutrition strategies require more planning and education.
Cons of Calorie Deficit
The potential drawbacks of a calorie deficit are:
- Low Energy Levels: with less available energy in the body, you might feel more fatigued. However, this can subside once the body adapts to a calorie deficit, assuming it is not an extreme deficit (e.g., 1000 calories or more).
- Negative Relationship With Food: when counting calories daily to reach your deficit, you can develop obsessive/restrictive behaviors with food and calories. Severe restriction and food obsession can cause malnutrition, nutrient deficiencies, and muscle wasting (loss).
- Slower Metabolism: when the body has less energy to maintain essential functions and support the muscles, it tries to conserve energy by slowing down the rate at which it expends energy. As your metabolic rate decreases, you will burn fewer calories (making it harder to lose weight).
Can You Do Carb Cycling & Calorie Deficit At The Same Time?
Yes, you can implement carb cycling and a calorie deficit simultaneously. Combining these approaches encourages weight loss, better athletic performance, and a leaner physique. However, this combination might only work for some people because it can be more challenging to adhere to.
For example, if you are new to tracking calories and macros, it might be overwhelming to start tracking these metrics and have them change daily.
Combining these approaches increases the potential for errors in calorie and macro calculations, food logging, and calorie estimations.
It also requires you to be organized and plan ahead. You must calculate your calorie deficit and incorporate carb cycling within your deficit, ensuring that macronutrients are balanced correctly to meet your needs according to your training routine.
It’s essential to ensure that carb cycling and a calorie deficit simultaneously align with your goals, preferences, and lifestyle to achieve sustainable results.
Will Carb Cycling or Calorie Deficit Be More Effective For Weight Loss?
Carb cycling will not help you lose weight unless you are in a calorie deficit; therefore, implementing a calorie deficit is more effective for weight loss than carb cycling.
It’s hard to say whether carb-cycling with a calorie deficit is better for weight loss than a calorie deficit alone (with no attention to macro intake) because research is lacking.
One study found that low-carb diets versus balanced-carb diets (both calorie-restricted) likely result in little to no difference in weight loss between the low-carb and balanced-carb subjects over three to six months, suggesting that the calorie deficit was most important for weight loss.
Based on the available research, we can conclude that the best weight loss strategy is the one you can best adhere to.
If you’re having success with your calorie deficit, then there may not be a need to implement carb cycling. However, if your performance is suffering from a deficit or weight loss has stalled, you should try introducing carb cycling.
6 Differences Between Carb Cycling vs Calorie Deficit
1. Dietary Data Focus
Carb cycling focuses on varying carbohydrate intake while keeping overall calories constant, whereas a calorie deficit emphasizes reducing overall calorie intake, regardless of macronutrient distribution.
2. Flexibility With Food Choices
Carb cycling calls for higher-carb, lower-fat days to align with workouts and thus requires more attention to detail with meal timing and macro distributions.
On the other hand, a calorie deficit provides more flexibility with food choices by negating the need for specific macro targets to be met.
Carb cycling fuels athletic performance, aids body recomposition, and breaks through weight loss plateaus. It is a more complex diet requiring regular adjustments, so it is best for more experienced dieters (e.g., bodybuilders).
A calorie deficit is used for weight loss with or without macro manipulation, making it a simple weight loss (or fat loss) approach for everyone.
4. Level of Nutrition Knowledge
With carb cycling, a good understanding of macronutrients (carbs, proteins, fats) is crucial for knowing when and how to adjust carbohydrate intake to match activity levels without changing your calorie target.
With a calorie deficit, awareness of the calorie content of foods is essential for tracking calorie intake and knowing how to create a deficit.
5. Variation in Meal Planning
Carb cycling requires planning different types of meals and snacks on high-carb and low-carb days and cooking foods separately, making meal planning more time-consuming.
On the other hand, a calorie deficit simplifies meal planning as it allows for more consistent meal choices.
6. Tracking and Adjustment
Carb cycling requires precise calorie and macro tracking and manipulation of carbohydrate (and fat) intake every few days.
To achieve a calorie deficit, you must monitor your calorie intake by calorie counting. However, this requires less effort and adjustments over time than carb cycling.
Who Should Do Carb Cycling?
Carb cycling is the best strategy for athletes or fitness enthusiasts to improve their strength-to-mass ratio or physical appearance.
While there is not enough research on carb cycling to conclude that it enhances performance, it is clear that carbs are the primary energy source for fueling workouts and recovery, so it certainly can’t hurt.
Who Should Do Calorie Deficit?
Those who want to lose weight and lower their body fat percentage must be in a calorie deficit.
If this is your first time pursuing weight loss and you are learning to monitor calories and energy intake/output, focus on achieving a calorie deficit, tracking your protein intake, and ignoring everything else.
Who Should Do Both?
Experienced dieters who want to maintain or increase physical fitness while losing fat should combine carb cycling with a calorie deficit.
I don’t recommend the combined approach for beginners as it can be overwhelming and set them up for failure.
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About The Author
Giulia Rossetto is a qualified Dietitian and Nutritionist. She holds a Masters in Human Nutrition (University of Sheffield, UK) and more recently graduated as a Dietitian (University of Malta). Giulia aims to translate evidence-based science to the public through teaching and writing content. She has worked 4+ years in clinical settings and has also published articles in academic journals. She is into running, swimming and weight lifting, and enjoys spending time in the mountains (she has a soft spot for hiking and skiing in the Italian Dolomites).
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