Intermittent Fasting and Carb Cycling: A Step-By-Step Guide
Dr. Mario Ost is a renowned nutrition scientist, researcher and lecturer, deeply invested in enhancing our basic understanding on mitochondrial fitness, muscle health, and endocrine organ crosstalk in sports, aging and metabolic diseases. He's a founder of a young athlete health academy and serves as a scientific advisor at Fastic, focusing on personalized nutrition concepts, fasting-mimicking food-components (autophagy-inducers) and benefits of exercise for metabolic homeostasis and healthy aging. As a devoted father and pioneer, Dr. Ost is shaping a future where elite athletes achieve peak performance and obese patients regain their metabolic and muscle health through an evidence-based approach on personalized training and nutrient timing.
Intermittent fasting and carb cycling are powerful strategies to boost metabolism, support weight loss, and help lower the risk of heart disease. But, can these two approaches be combined, and if so, how much additional benefit can they offer for your health?
Continue reading to find out if combining carb cycling and intermittent fasting is ideal for your wellness goals.
What Is Intermittent Fasting?
Intermittent fasting consists of alternating between fasting periods and eating windows. During the eating window, one can eat your usual diet, whereas during fasting periods one can only drink calorie-free beverages such as water infused with low-calorie fruits, calorie-free electrolyte beverages, or plain-black coffee to avoid interfering with the body’s fasted state. Fasting apps like Fastic help you track water intake to ensure optimal hydration during fasting. The most common intermittent fasting protocols are 14:10 and 16:8; however, many other intermittent fasting schedules are also available.
Benefits of Intermittent Fasting:
Help with weight loss and weight management.
Improve HDL cholesterol and insulin sensitivity.
Enhance cognitive function.
Increase neuroplasticity and resistance to injury and disease.
Encourage cellular repair and longevity.
What Is Carb Cycling?
Carb cycling involves alternating low-carb, moderate-carb, and high-carb days over a specified period, whether daily, weekly, or monthly. The primary objective of carb cycling is to maximize its benefits and limit intake when it isn’t required. While there isn’t a definitive carbohydrate intake or structure to follow, it largely depends on individual activity levels, muscle mass, and carbohydrate sensitivity, which genetic or metabolic factors can influence.
Benefits of Carb Cycling:
Encourage weight loss (combined with resistance exercise and calorie deficit).
Promote muscle growth and maintenance.
Improve body composition (combined with high-intensity exercise).
The Synergy of Intermittent Fasting and Carb Cycling
Combining intermittent fasting with carb cycling may offer several potential benefits. Here’s how these two wellness strategies work together:
Increase metabolic flexibility by constantly alternating between energy sources (fats and carbohydrates).
Support fat oxidation on low-carb days, promoting a more efficient fat-burning process.
Improve energy levels for intense workouts by timing carbohydrate intake around workouts to replenish glycogen stores and enhance performance.
Promote muscle recovery and growth, helping to maintain lean muscle mass with adequate protein and nutrient timing.
Aid in blood sugar regulation by enhancing insulin sensitivity in some individuals.
Encourage dietary flexibility for a more adaptable eating schedule, supporting long-term adherence.
How to Calculate Carbohydrate Intake for Carb Cycling
The Dietary Guidelines for Americans recommend that carbohydrates comprise 45% to 65% of total daily calories.
A typical carb cycling approach may include:
High-carb days: 45-65% of total calories
Moderate-carb days: 30-40% of total calories
Low-carb days: 10-20% of total calories
Here’s how to convert these percentages into total grams of carbohydrates based on a 2000-calorie diet.
Step 1: Calculate Total Carbohydrate Calories:
For a 2000-calorie diet, the carbohydrate calories based on each cycle day are as follows:
High-carb days: 900-1300 calories from carbs
Moderate-carb days: 600-800 calories from carbs
Low-carb days: 200-400 calories from carbs
Step 2: Calculate Calories to Grams:
Since 1 gram of carbohydrates provides 4 calories, divide the total carbohydrate calories by 4:
High-carb days: 900 ÷ 4 = 225 grams; 1300 ÷ 4 = 325 grams
Moderate-carb days: 600 ÷ 4 = 150 grams; 800 ÷ 4 = 200 grams
Low-carb days: 200 ÷ 4 = 50 grams; 400 ÷ 4 = 100 grams
These values can vary depending on daily calorie intake and preferences. It is recommended to plan high-intensity workouts on high-carb days to maximize performance. Low-carb days can be useful on rest days, while no-carb days are optional and may suit some people on non-workout days, although many individuals find low-carb days sufficient for managing energy needs. To simplify carb calculations, consider using tools like the Fastic app, that provide carbohydrate calculators. This helps you focus on your fasting and carb cycling routine without the need for constant manual tracking.
How To Combine Intermittent Fasting and Carb Cycling
Combining intermittent fasting and carb cycling is not as complicated as it seems. Let’s take a look at how you can effectively merge these two strategies according to your routine and preferences.
Choose an intermittent fasting protocol
Determine which fasting protocol works best with your work schedule, daily responsibilities, physical activity levels, and health goals. Intermittent fasting protocols vary in fasting period length, making it possible to choose one that fits your daily routine.
Define your carb cycling structure
Once you’ve determined your fasting protocol, define your carb cycling intake and schedule. The amount of carbs can vary depending on your body weight, physical activity levels, and health objectives.
Example schedule of intermittent fasting and carb cycling
Here’s a sample weekly schedule for intermittent fasting and carb cycling using the 16:8 protocol, which involves 16 hours of fasting followed by an 8-hour eating window.
Day | Carb Level | Carb Intake | Exercise Level |
Monday | High | 225-325 grams | Intense |
Tuesday | Low | 50-100 grams | Light |
Wednesday | Moderate | 150-200 grams | Moderate |
Thursday | High | 225-325 grams | Intense |
Friday | Low | 50-100 grams | Light |
Saturday | High | 225-325 grams | Intense |
Sunday | No-carb/ Very low-carb | <30 | Rest day |
The schedule doesn’t need to be consistent each week. Feel free to experiment with different combinations to define a structure that best suits your needs. Remember, carbohydrate intake is entirely based on your personal preferences.
Maximize Your Fasting and Carb Cycling Efforts
To achieve optimal health while combining intermittent fasting and carb cycling, consider the following tips.
Hydration is crucial for maintaining energy levels, feeling satiated, and supporting metabolic processes. Drink plenty of water and calorie-free, electrolyte-rich beverages to replenish essential nutrients lost during exercise.
Help maintain muscle mass and promote recovery by including lean protein sources in meals and considering high-quality protein shakes during your eating window.
Focus on high-fiber foods, whole grains, and legumes. Choose low-fat milk, cheese, yogurt, and other dairy products.
Always listen to your body’s signals and make adjustments as necessary. These dietary strategies allow for flexibility in structure and intensity.
Who Can Benefit from Intermittent Fasting and Carb Cycling?
Individuals looking to lose fat while preserving muscle mass:
These strategies support the maintenance of lean tissue.
Athletes or fitness enthusiasts
Those who require adaptable energy levels and are looking to enhance endurance and boost performance.
Individuals struggling with insulin resistance
Those who need help stabilizing blood sugar and improving insulin response.
Consider giving intermittent fasting and carb cycling a try! Discover how combining these two wellness approaches can maximize your efforts and guide you toward optimal health. Take the Fastic quiz to find out which fasting protocol is best suited for your routine and objectives.
Disclaimer: It is advised to speak with a health professional before beginning intermittent fasting or a diet program. There may be side effects for people with certain medical conditions.
With Fastic, millions of people have achieved their desired weight, overcome disease and regained their quality of life.
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