The amount of carbohydrates a person needs daily is a dynamic number influenced by their body weight, activity level, fitness goals, and metabolic health. Moving beyond general percentages, using a gram-per-kilogram (g/kg) body weight approach allows for a far more precise calculation. This method, backed by sports nutrition science, provides actionable targets whether you are aiming for weight loss, muscle gain, or peak athletic performance.
The Sedentary and Lightly Active
For those with a low level of physical activity, the body's energy demands are minimal, and so are its carbohydrate requirements. The primary function of carbohydrates in this case is to provide fuel for essential bodily functions, especially for brain function, which typically requires about 130 grams of glucose per day.
Recommended Intake
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For sedentary or very light activity: 3-5 grams of carbohydrate per kilogram of body weight per day.
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Example Calculation: A 70kg sedentary individual would aim for 210 to 350 grams of carbohydrates daily (70kg x 3g/kg and 70kg x 5g/kg).
Consuming within this range, while focusing on nutrient-dense, high-fiber carbohydrate sources like whole grains, vegetables, and fruits, supports overall health and provides sustained energy.
Fueling for Moderate Training and Muscle Gain
As activity levels increase, so does the body's need for glycogen—the stored form of carbohydrates. Moderate trainers and those focused on muscle hypertrophy (growth) require more fuel to support both performance during workouts and recovery afterward.
Recommended Intake
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For moderate training (around 1 hour per day): 5-7 g/kg/day.
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For strength athletes focusing on muscle gain: 4-7 g/kg/day, with intake tailored around training sessions.
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Post-Workout Recovery: Consuming 1.0-1.2 g/kg of carbohydrates within the first few hours after intense exercise is critical for replenishing muscle glycogen stores quickly and promoting muscle repair.
Powering Elite Endurance and Performance
Endurance athletes and individuals with very high training volumes have the highest carbohydrate needs. Their extensive training schedules rapidly deplete muscle and liver glycogen, and consistent, high-level carb intake is necessary to maintain performance and avoid fatigue.
Recommended Intake
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For high-intensity endurance training (1-3 hours per day): 6-10 g/kg/day.
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For very high-intensity training or carb loading (>4 hours per day): 8-12 g/kg/day.
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Intra-workout fuel: During prolonged exercise sessions (over 60 minutes), ingesting 30-90+ grams of carbs per hour is recommended to maintain performance and delay fatigue.
The Role of Carbs in Weight Loss
Contrary to popular belief, carbohydrates do not need to be eliminated for successful weight loss. The key is moderation and prioritizing diet quality. A moderate carb intake supports energy levels for workouts while a calorie deficit drives weight loss.
Recommended Intake
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For fat loss: A more moderate intake of 1-3 g/kg/day is often recommended, especially for those who are physically active.
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Ketogenic Diets: These are a specialized form of very low-carb dieting, typically under 50g of total carbs per day, designed to induce ketosis. This approach is not based on a g/kg calculation but on an absolute daily limit.
Comparison of Carb Intake by Activity Level
To visualize the significant variation in carbohydrate requirements, the following table compares intake across different activity levels based on a 70kg individual.
| Activity Level | Daily Carb Target (g/kg) | Example (70kg Person) | Focus |
|---|---|---|---|
| Sedentary | 3-5 g/kg | 210-350 grams | Brain function, fiber intake |
| Moderate Training (~1 hour) | 5-7 g/kg | 350-490 grams | Energy for performance & recovery |
| High Endurance Training | 6-10 g/kg | 420-700 grams | Glycogen replenishment |
| Very High Endurance | 8-12 g/kg | 560-840 grams | Maximizing glycogen stores |
| Weight Loss (Active) | 1-3 g/kg | 70-210 grams | Prioritizing nutrient timing |
How to Calculate and Adjust Your Intake
To determine your personalized intake, start by converting your weight from pounds to kilograms by dividing by 2.2. Then, multiply your weight in kg by the appropriate g/kg range for your activity level and goals. For example, a 150lb (68kg) person with moderate training needs would calculate 68kg x (5-7g/kg) = 340-476g of carbs per day. This number can then be distributed throughout the day, paying special attention to fueling around workouts for optimal performance.
Tips for Success
- Prioritize Nutrient-Dense Carbs: Choose quality sources like whole grains, vegetables, fruits, and legumes.
- Time Your Intake: Consume carbs strategically before, during (for long sessions), and after exercise to maximize performance and recovery.
- Listen to Your Body: Pay attention to how different levels of carb intake affect your energy, hunger, and performance. Use these guidelines as a starting point and adjust based on what works for you.
- Consult a Professional: A registered dietitian or sports nutritionist can offer tailored advice to help you fine-tune your macronutrient strategy for specific goals and health needs.
Conclusion
There is no single correct answer to the question of how many carbs per kg per day; the optimal amount is a moving target that depends entirely on individual factors. By using body weight as a baseline and scaling your intake according to your activity level and fitness objectives, you can create a highly effective fueling strategy. From the modest needs of a sedentary person to the super-charged requirements of an ultra-endurance athlete, adjusting carbohydrate intake by body weight is a scientifically-backed method for optimizing energy, performance, and health. For further reading on the scientific basis of carbohydrate intake for performance, consider this resource from the National Institutes of Health: The Effect of Carbohydrate Intake on Strength and Resistance Exercise Performance.
What are some examples of high-carb foods recommended for athletes?
- Whole Grains: Oatmeal, brown rice, quinoa, and whole-wheat bread provide slow-releasing energy.
- Starchy Vegetables: Sweet potatoes, potatoes, and corn offer nutrient-dense carbohydrates.
- Fruits: Bananas, berries, and apples are great sources of natural sugars and antioxidants.
- Legumes: Lentils, beans, and chickpeas are excellent for sustained energy and fiber.
- Sports Nutrition: Gels, energy bars, and sports drinks are formulated for quick absorption during exercise.
Can I still lose weight on a higher carb intake?
Yes, weight loss is fundamentally about maintaining a calorie deficit. While reducing carbs can be one strategy, maintaining a moderate intake that fuels exercise can actually support a higher metabolism and prevent side effects associated with very low-carb diets, such as fatigue and hair loss.
What are the signs of insufficient carbohydrate intake?
Signs of under-fueling with carbohydrates can include persistent fatigue, poor workout performance, difficulty recovering, mood changes, and a weakened immune system. For athletes, low glycogen levels can lead to a significant drop in high-intensity performance.
What is carb loading and who should do it?
Carb loading is a strategy for endurance athletes competing in events lasting over 90 minutes. It involves increasing carbohydrate intake to 8-12 g/kg/day for 1-3 days while tapering exercise, which maximizes muscle glycogen stores to extend endurance. It is not necessary for shorter events or lower intensity activities.
Is it better to eat simple or complex carbs?
Both simple and complex carbs have a place in a balanced diet, but their timing is key. For general daily fuel, prioritize complex carbs (e.g., whole grains) for sustained energy. Simple carbs (e.g., fruit, gels) are more beneficial immediately before, during, or after intense exercise for rapid energy and glycogen replenishment.
Do I need different amounts of carbs on training days versus rest days?
Yes, many athletes and trainers practice periodized nutrition or carb cycling, where carbohydrate intake is higher on heavy training days and lower on rest days. This matches fuel intake with energy expenditure and can help manage body composition.
How many carbohydrates should a 75kg individual eating for muscle gain consume?
For a 75kg person aiming for muscle gain, following the 4-7 g/kg range suggests a daily intake of 300 to 525 grams of carbohydrates (75kg x 4g/kg to 75kg x 7g/kg). This range provides ample energy to support intense training and recovery.
