Body recomposition, building muscle while losing fat at the same time, requires eating at or slightly below your maintenance calories with a specific macro split that prioritizes protein. The exact numbers depend on your body weight, activity level, and how much fat you have to lose, but the process for calculating them is straightforward once you know the steps.
Step 1: Find Your Maintenance Calories
Before setting macros, you need to know how many calories your body burns in a day. This is your Total Daily Energy Expenditure, or TDEE. The most reliable way to estimate it starts with calculating your Basal Metabolic Rate (BMR) using the Mifflin-St Jeor equation:
- Men: (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) + 5
- Women: (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) − 161
To convert pounds to kilograms, divide by 2.2. To convert inches to centimeters, multiply by 2.54. Once you have your BMR, multiply it by an activity factor to get your TDEE:
- Sedentary (desk job, little exercise): BMR × 1.2
- Lightly active (exercise 1–3 days/week): BMR × 1.375
- Moderately active (exercise 3–5 days/week): BMR × 1.55
- Active (exercise 6–7 days/week): BMR × 1.725
- Very active (hard daily training or physical job): BMR × 1.9
A common mistake is overestimating activity level. If you lift weights three times a week but sit at a desk the rest of the day, “lightly active” is probably more accurate than “moderately active.” You can always adjust after two to three weeks based on what your weight and measurements are doing.
Step 2: Set Your Calorie Target
Body recomposition doesn’t require a steep calorie deficit. In fact, too large a deficit makes it nearly impossible to build muscle because your body won’t partition enough energy toward new tissue. Most people do best eating at maintenance calories or in a mild deficit of about 10 to 20 percent below TDEE. For someone with a TDEE of 2,400 calories, that means eating somewhere between 1,920 and 2,400 calories per day.
If you carry a significant amount of body fat, you can tolerate a slightly larger deficit (closer to 20 percent) and still gain muscle, especially if you’re newer to resistance training. If you’re already relatively lean, staying closer to maintenance or even eating at a very slight surplus on training days gives your body more raw material to build with. The leaner you are, the harder simultaneous fat loss and muscle gain becomes, and the more precise your nutrition needs to be.
Step 3: Calculate Protein First
Protein is the most important macro for recomposition, and it’s the one you calculate before anything else. When you’re trying to gain muscle in a calorie deficit, your protein needs are higher than someone who’s simply maintaining weight. Research supports a range of 1.6 to 2.4 grams of protein per kilogram of body weight per day for people aiming to lose fat while maximizing muscle gain on a reduced-calorie diet.
For practical purposes, here’s what that looks like:
- 150 lb (68 kg) person: 109–163 g protein per day
- 180 lb (82 kg) person: 131–197 g protein per day
- 220 lb (100 kg) person: 160–240 g protein per day
If you carry a lot of extra body fat, use a target closer to the lower end of the range (1.2 to 1.6 g/kg), since the formula is based on total body weight and excess fat tissue doesn’t require the same protein support that lean mass does. If you’re at a healthy weight or already somewhat muscular, aim for the higher end, around 2.0 to 2.4 g/kg. Each gram of protein contains 4 calories, so multiply your protein grams by 4 to find how many of your daily calories are spoken for.
Step 4: Set Your Fat Intake
Dietary fat supports hormone production, including testosterone and other hormones critical for muscle building. Dropping fat too low can stall your progress. A good baseline is 25 to 35 percent of your total daily calories from fat. Each gram of fat contains 9 calories.
Using the example of a 180 lb person eating 2,200 calories with a protein target of 165 g:
- Protein calories: 165 g × 4 = 660 calories
- Fat at 30%: 2,200 × 0.30 = 660 calories ÷ 9 = 73 g fat
If you feel better on slightly higher fat, push toward 35 percent. If you prefer more carbs for energy during training, drop fat closer to 25 percent. Just don’t go below about 0.5 grams of fat per pound of body weight as a floor for hormonal health.
Step 5: Fill the Rest With Carbs
Once protein and fat are set, the remaining calories go to carbohydrates. Each gram of carbs contains 4 calories. Continuing the example above:
- Total calories: 2,200
- Protein: 660 calories
- Fat: 660 calories
- Remaining for carbs: 2,200 − 660 − 660 = 880 calories ÷ 4 = 220 g carbs
Carbs fuel your training sessions and recovery. Cutting them too aggressively can reduce workout performance, which limits the stimulus your muscles receive. For recomposition specifically, having enough carbs to train hard matters more than minimizing them.
How to Distribute Protein Throughout the Day
Hitting your daily protein target matters most, but how you spread it across meals can make a meaningful difference. After you eat protein, your body ramps up muscle-building activity for roughly two to three hours before it tapers off regardless of how much protein was in the meal. This means eating one massive serving of protein at dinner and neglecting it the rest of the day is less effective than splitting your intake across three to five meals.
For adults under 30, muscle-building response scales fairly linearly with how much protein is in a meal, so even smaller servings contribute meaningfully. For adults over 60, meals need to contain at least about 30 grams of protein (providing roughly 2.8 grams of the amino acid leucine) to reliably trigger a strong muscle-building response. Regardless of age, spreading 25 to 40 grams of protein across each meal is a reliable approach.
A Complete Example
Here’s the full calculation for a 35-year-old man, 5’10” (178 cm), 185 lbs (84 kg), who lifts weights four days a week and has a desk job:
BMR: (10 × 84) + (6.25 × 178) − (5 × 35) + 5 = 840 + 1,112.5 − 175 + 5 = 1,782 calories
TDEE: 1,782 × 1.375 (lightly active) = 2,450 calories
Recomp target (slight deficit of ~15%): 2,450 × 0.85 = 2,080 calories
Protein (2.0 g/kg): 84 × 2.0 = 168 g → 672 calories
Fat (30% of calories): 2,080 × 0.30 = 624 calories → 69 g
Carbs (remainder): 2,080 − 672 − 624 = 784 calories → 196 g
His daily macros: 168 g protein, 69 g fat, 196 g carbs.
Adjusting Over Time
These numbers are a starting point, not a permanent prescription. Track your weight, how your clothes fit, and your performance in the gym for two to three weeks before changing anything. Body recomposition is slower than straight cutting or bulking, so the scale may barely move even when your body is changing composition. Progress photos every two to four weeks and strength trends in your training log are better indicators than the scale alone.
If you’re losing more than about one pound per week, you’re likely in too steep a deficit and risk losing muscle. Add 100 to 200 calories from carbs. If your weight is steadily climbing after the first couple of weeks (and you’re not a complete beginner), you’re eating above maintenance. Trim 100 to 200 calories, again primarily from carbs or fat, and keep protein where it is. Protein is the last macro you should reduce.