When our body is in a caloric deficit, it consumes fewer calories than it expends, drawing on its fat reserves to provide energy. The calculation of the caloric deficit to adopt for weight loss is specific to each individual.
To calculate it, first determine your daily caloric requirements using your basal metabolic rate and your physical activity expenditure, then decide on the appropriate deficit.
When you're on a diet, the deficit is generally between 300 and 500 kcal/day compared with your total calorie requirement. Let's take a look at how to calculate your caloric needs and deficit precisely, so you can achieve results without compromising your health or sporting performance.
What is the caloric deficit formula?
The calorie deficit formula to aim for depends on your weight loss goal and your Total Daily Energy Expenditure(TDEE).
Here's the general formula:
Caloric deficit = TDEE - Daily caloric intake
TDEE is the number of calories you burn per day, based on your Basal Metabolic Rate(BMR) and activity level.
It is calculated as follows
TDEE = BMR × Activity factor
The TDEE formula is therefore relatively straightforward, and the complexity lies in determining the Basic Metabolic Requirement (BMR).
BMR can be estimated using various formulas. The best known, and the one we use in our calculator, is the Black & All formula:
- Men: BMR = 259 × (weight in kg)^0.48 × (height in m)^0.50 × (age)^-0.13
- Women: BMR = 230 × (weight in kg)^0.48 × (height in m)^0.50 × (age)^-0.13
If you are interested in this subject, there is another well-known but less accepted formula, the Mifflin-St Jeor formula:
- Men: BMR=(10×Weight in kg)+(6.25×Height in cm)-(5×Age)+5
- Women: BMR=(10×Weight in kg)+(6.25×Height in cm)-(5×Age)-161
Finally, the activity factor depends on your level of exercise and ranges from ×1.9 to ×1.725 .
Let's look at the main differences:
- Complexity: Black's formula uses non-integer powers, making it more complex to calculate but potentially more accurate.
- Database: Black used a meta-analysis of double-labeled water energy expenditure measurements, considered to be one of the most accurate methods.
- Accuracy: Black's formula is often considered more accurate for specific populations, such as the obese.
- Non-linear relationship: Black's formula recognizes that the relationship between weight and BMR is not strictly linear (exponent 0.48 for weight).
- Consideration of height: Black's formula gives greater weight to height (better reflecting body composition).
What is the caloric deficit?
To lose weight, you need to expend more energy than you consume. To achieve this imbalance, it is possible to create a calculated caloric deficit by controlling your diet, in order to push your body to draw on its reserves.
The energy burned depends on :
- Basic metabolism: this represents the calories required for the vital functioning of the body at rest.
- Energy expenditure linked to daily physical activity.
Energy balance calculator
Too great a deficit can lead to muscle loss, excessive fatigue and hormonal imbalances.
Muscle leaning is not simply a matter of losing weight. The aim is to maintain an adequate macronutrient intake and adopt a moderate caloric deficit in order to reduce body fat while preserving lean body mass.
Whey is often consumed by athletes during their dry periods to ensure sufficient protein intake while controlling caloric intake.
It's advisable not to lose more than 2 kg per month during a dry period, to avoid disrupting the metabolism.
Be careful not to stop eating abruptly in order to dry out quickly. Reduction is done intelligently by adjusting macronutrients (proteins, carbohydrates, lipids) to promote muscle preservation and the use of fat as an energy source.
How to calculate the caloric deficit for dry weight training?
Caloric and macronutrient requirements calculator
Recommended macronutrient breakdown (approx.)
The first step in calculating your caloric needs is to estimate the caloric expenditure linked to your basal metabolic rate : i.e. the quantity of calories your body needs daily at rest to maintain its vital functions, such as respiration and thermogenesis.
This amount depends on gender, weight, height and age. For this calculation, our calculator uses the reference formula of Black et al.
The next step is to estimate the number of calories your body burns during exercise. There are various methods available on the Internet to help you estimate these calories expended (connected watches, specialized sites...), and a formula for the majority of sports is already integrated into this calorie deficit calculator.
Athletes on a lean period often combine resistance exercise to stimulate and maintain muscle mass, with endurance activity to increase their energy expenditure.
To create a caloric deficit suitable for a lean period, we then recommend that you gradually reduce this energy intake each week, until you reach 300 to 500 kcal per day.
During a low-calorie diet, the body becomes more thrifty with energy, naturally slowing down fat loss - a process known as metabolic adaptation. This is why you need to be progressive in both the reduction and reintroduction phases.
What macronutrient ratios?
Adopting the right macronutrient distribution when adjusting your daily calorie intake is no easy task. A good lean program is based on a precise calculation of the caloric deficit according to current weight, lifestyle (sedentary or active), age in years and basal metabolic rate (BMR), optimized training and, above all, a balanced diet.
In general, the recommended macronutrient breakdown is around 20-25% protein, 50-55% carbohydrates and 25-30% fat (as a % of total calorie intake) , but this can vary to a greater or lesser extent depending on the athlete's profile. In fact, it can vary greatly according to weight and personal objectives. For example, a very light profile (60 kg) building mass will need around 3,000 to 3,500 kcal per day. If we respect the 20-25% protein rule, this would mean between 150 and 187.5 g/kg of protein, i.e. between 2.5 and 3.12 g/kg, which is far too high.
It should therefore be remembered that these % are indicative and, above all, not adapted to athletes' specific objectives.
Energy values of macronutrients :
- Protein: 4 kilocalories per 1 gram
- Carbohydrates: 4 kilocalories per 1 gram
- Fat: 9 kilocalories per 1 gram
How much protein should I eat when I'm dry?
A well-controlled caloric deficit should avoid muscle catabolism while promoting the reduction of body fat.
Protein plays an essential role in rebuilding muscle tissue. In the absence of adequate protein intake, the body risks drawing on its muscle reserves.
An optimal intake is between 1.5 and 2 grams per kilo of body weight per day. For example, an individual weighing 70 kilos should consume between 105 and 140 grams of protein daily.
Optimal protein intake calculator
Recommended daily protein intake (for an athlete with no particular health problems): 119g
Optimal protein intake is between 1.5 and 2 grams per kilo of body weight per day.
Sporting activity influences these requirements: an active athlete will need to adjust his or her protein intake to the muscular effort expended during the session.
How many carbohydrates do you need during a dry run?
A gradual reduction in carbohydrates is recommended to promote effective calorie restriction without negatively impacting basal metabolic rate.
Carbohydrates are essential and should not be completely eliminated, as this can lead to hormonal imbalances and excessive fatigue.
The recommended carbohydrate intake is between 2.8 and 3.8 grams per kilo of body weight per day, depending on your level of physical activity.
→ 2.8 g/kg: moderate activity or weight loss goal
→ 4 g/kg: intense activity or endurance sports
Recommended carbohydrate intake calculator
Recommended daily carbohydrate intake:
Which glycemic index to choose?
The glycemic index of foods is an important factor in choosing these foods. Complex carbohydrates such as brown rice or quinoa are preferable because they offer several benefits:
- A stable supply of energy, preventing fatigue attacks
- Fewer fluctuations in blood sugar levels, limiting excessive insulin secretion (excess insulin promotes fat storage)
- Better hunger management, reducing cravings and food gaps
Theglycemic index (GI) measures the rate at which a carbohydrate-containing food raises blood sugar levels.
A high-GI food, such as white bread, causes a rapid rise in blood sugar and a spike in insulin. A low-GI food like oatmeal releases glucose gradually, avoiding these sudden variations.
- Low glycemic index (≤ 55): slow release of glucose, stable energy
- Average glycemic index (56-69): moderate glucose release
- High glycemic index (≥ 70): energy and insulin peaks, rapid energy loss
Insulin enables glucose to be stored in the form of glycogen, but an unused excess is converted into fat. In the dry period, the aim is to limit this storage and encourage the mobilization of reserves. Avoiding high-GI foods reduces insulin spikes and thus the tendency to store fat.
Energy level
Insulin level
This visualization is for comprehension purposes only. The curves are simplified and the data do not represent actual measurements.
Should I stop eating fat when I'm on a diet?
Dietary fats are often the first to be reduced in times of caloric deficit, as they are higher in calories than proteins and carbohydrates. Nevertheless, they are an important part of any diet, as they help maintain a healthy hormonal balance.
Excessive lipid reduction can :
- disrupt basal metabolism
- impact on fitness
- slow down weight loss.
When dry, athletes should aim for between 0.8 and 1.2 grams of lipids per kg of body weight.
Recommended fat intake calculator for athletes
Recommended daily fat intake:
The body needs omega-3 and omega-6 from the diet, as it cannot synthesize them on its own. They must be incorporated via foods rich in unsaturated fatty acids, such as oily fish, nuts and certain vegetable oils.
Do endomorphs, ectomorphs and mesomorphs have the same daily macronutrient requirements?
According to some studies, the macronutrient content should be adapted to the athlete's profile. A study from 20241 highlights the link between differences in morphotypes and differences in diet among professional athletes.
This cross-sectional study examined the somatotypic profiles, body composition and nutritional intakes of 189 elite Lithuanian athletes involved in aquatics, cycling and combat sports.
Significant associations were observed between the endomorphic and mesomorphic components with a higher percentage of body fat, as well as with upper and lower limb muscle mass.
Mesomorphic athletes tended to consume low-carbohydrate, high-protein diets, while those with higher endomorphic expression followed high-carbohydrate, high-fat diets with insufficient protein intake.
People who are naturally more endomorphic (tend to store fat easily) could benefit from an approach with fewer carbohydrates and more protein during a dry phase, while ectomorphs (difficulty gaining weight) can generally tolerate more carbohydrates even in caloric deficit.
Modern science, however, is moving away from a rigid categorization of morphotypes (ectomorph, mesomorph, endomorph) in favor of a more individualized approach based on measurable physiological markers such as body composition, hormonal response and insulin sensitivity.
Should I reduce my caloric deficit to 0 when I stop leaning?
The end of the dry period is a phase that must not be neglected. Reintroducing calories too abruptly can lead to rapid fat regain.
Reverse dieting refers to a gradual increase in daily caloric intake until the body returns to a normal caloric diet. The aim is to enable the basal metabolic rate to adapt gradually to the increased calories, preventing fat storage.
Theyo-yo effect occurs mainly after drastic calorie restriction, followed by a rapid return to a normal diet. The metabolism, slowed down by the dryness, tends to store the sudden surplus of calories.
Getting back to normal calorie requirements can take several weeks, depending on the duration and intensity of the previous dry period: a reduction in the calorie deficit of around 100 to 200 kcal per week is often advisable.
Calorie deficit reduction calculator
Estimated time to return to normal caloric requirements:
This calculator gives an estimate based on a constant progressive reduction. Adjust according to how you feel and your personal goals.
Recommendations:
- Too rapid a reduction may compromise metabolic stabilization
- Monitor your energy and performance during the transition
- Adapt the reduction speed to your personal needs
Conclusion
Calculating the right caloric deficit is essential for any athlete wishing to achieve muscle lean. The balance between caloric restriction and preservation of lean body mass is based on a methodical approach specific to each individual.
Our calculator takes into account both basal metabolic rate and physical activity, so everyone can accurately determine their daily calorie requirement. We recommend a calorie reduction of 300-500 kcal per day to promote body fat loss and maintain muscle mass.
During the restriction phase, balanced macronutrient distribution is essential to ensure complete nutrition and avoid future weight gain. It is advisable to consume carbohydrates around exercise sessions to maximize the energy expended, but also afterwards with proteins to promote recovery.
