Calorie Requirements

📊 Calorie Intake Report (Using Mifflin–St Jeor)

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1. Formula Used: Mifflin–St Jeor Equation

Men:

$$BMR = (10 \times \text{Weight (kg)}) + (6.25 \times \text{Height (cm)}) - (5 \times \text{Age}) + 5$$

Women:

$$BMR = (10 \times \text{Weight (kg)}) + (6.25 \times \text{Height (cm)}) - (5 \times \text{Age}) - 161$$

• BMR (Basal Metabolic Rate): Calories burned at complete rest (if you did nothing all day).
• This is the starting point before adjusting for lifestyle.

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2. Inputs Needed

• Weight: in kilograms
• Height: in centimeters
• Age: in years
• Sex: male or female
• Activity Level (Lifestyle): see section 4

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3. Outputs

• BMR (Basal Metabolic Rate): Calories needed at rest.
• TDEE (Total Daily Energy Expenditure): Calories needed to maintain weight based on lifestyle.

$$TDEE = BMR \times \text{Lifestyle Multiplier}$$

• Weight loss intake: ~TDEE − 500 kcal/day (≈ 0.5 kg/week loss).
• Weight gain intake: ~TDEE + 300–500 kcal/day (≈ 0.25–0.5 kg/week gain).

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4. Lifestyle Multipliers (Activity Factors)

This part often causes confusion because "active" means very different things to different people. Here’s the standard classification:

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5. Example Calculation

Person: Male, 70 kg, 175 cm, 24 years, Moderately Active

• Step 1 – BMR:

$$BMR = (10 \times 70) + (6.25 \times 175) - (5 \times 24) + 5 = 1,698 \text{ kcal}$$

• Step 2 – TDEE (Moderately Active = ×1.55):

$$TDEE = 1,698 \times 1.55 \approx 2,632 \text{ kcal/day}$$

• Step 3 – Adjust for Goal:

  • Maintain: ~2,632 kcal/day
  • Weight loss: ~2,132 kcal/day
  • Weight gain: ~2,932–3,132 kcal/day

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✅ Takeaway:

• BMR = baseline needs at rest.
• Lifestyle multiplier = accounts for daily movement/exercise.
• TDEE = your "maintenance calories."
• From TDEE, adjust up or down depending on goal.