How It Works

Understanding the science behind calorie calculations helps you make informed decisions about your health. Learn how we determine your personalized calorie targets using proven scientific methods.

The Calculation Process

Step 1: BMR Calculation

We calculate your Basal Metabolic Rate using the scientifically validated Mifflin-St Jeor equation, which accounts for your age, gender, height, and weight.

Step 2: Activity Factor

Your BMR is multiplied by an activity factor (1.2-1.9) based on your daily activity level to calculate your Total Daily Energy Expenditure (TDEE).

Step 3: Goal Adjustment

We create different calorie targets by adjusting your TDEE: maintenance (TDEE), mild loss (TDEE - 250), weight loss (TDEE - 500), and extreme loss (TDEE - 1000).

Step 4: Results

You receive personalized daily calorie targets with expected weight loss rates, helping you choose the approach that best fits your goals and lifestyle.

Understanding BMR (Basal Metabolic Rate)

Your Basal Metabolic Rate (BMR) represents the minimum number of calories your body needs to maintain basic physiological functions while at complete rest. This includes:

  • • Breathing and circulation
  • • Cell production and repair
  • • Protein synthesis
  • • Brain and nervous system function
  • • Maintaining body temperature

Mifflin-St Jeor Equation

Men:
BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age + 5
Women:
BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age - 161

From BMR to TDEE

Your Total Daily Energy Expenditure (TDEE) is your BMR multiplied by an activity factor that accounts for your daily movement and exercise. This gives you the total calories you burn in a typical day.

Sedentary (BMR × 1.2)

Little to no exercise, desk job, minimal daily activity

Lightly Active (BMR × 1.375)

Light exercise 1-3 days per week, some walking

Moderately Active (BMR × 1.55)

Moderate exercise 3-5 days per week, active lifestyle

Very Active (BMR × 1.725)

Hard exercise 6-7 days per week, very active job

Extra Active (BMR × 1.9)

Very hard exercise, physical job, training twice daily

The Science of Calorie Deficits

Weight loss occurs when you consistently consume fewer calories than you burn, creating an energy deficit. Your body then uses stored energy (primarily fat) to meet its energy needs.

250 Calorie Deficit

≈ 0.25 kg per week

Conservative, sustainable approach

500 Calorie Deficit

≈ 0.5 kg per week

Most commonly recommended

1000 Calorie Deficit

≈ 1 kg per week

Aggressive, requires supervision

Important Considerations

  • Individual Variation: Metabolic rates can vary by ±15% between individuals due to genetics, muscle mass, and other factors.
  • Adaptive Response: Your metabolism may slow down during prolonged calorie restriction, requiring periodic adjustments.
  • Non-Linear Progress: Weight loss isn't always consistent due to water retention, hormonal fluctuations, and other factors.
  • Professional Guidance: These calculations provide estimates. Consult healthcare professionals for personalized advice.