FAQ

What is TDEE?

TDEE (Total Daily Energy Expenditure) is the estimated number of calories you burn per day based on your Basal Metabolic Rate (BMR) and physical activity level.

How is BMR calculated?

We use the Mifflin-St Jeor Equation:


      For men: BMR = 10 × weight (kg) + 6.25 × height (cm) – 5 × age (y) + 5

      For women: BMR = 10 × weight (kg) + 6.25 × height (cm) – 5 × age (y) – 161

Source: Mifflin MD, St Jeor ST

How is TDEE calculated?

We multiply your BMR by your activity factor:

Sedentary (little or no exercise): × 1.2
Light activity (1–3 days/week): × 1.375
Moderate activity (3–5 days/week): × 1.55
Very active (6–7 days/week): × 1.725
Extra active (physical job or twice daily training): × 1.9

CDC – Centers for Disease Control and Prevention: Understanding Calories and Energy Expenditure
NIH – National Institutes of Health: Body Weight Planner and TDEE Calculation
USDA – United States Department of Agriculture: MyPlate Plan Based on Activity Level
PubMed (Peer-reviewed research): Total Energy Expenditure: Components and Assessment Methods

What is BMI and how is it calculated?

BMI (Body Mass Index) is a simple index of weight-for-height used to classify underweight, normal weight, overweight, and obesity.

BMI = weight (kg) / (height (m) × height (m))

According to the World Health Organization (WHO):

BMI < 18.5 — Underweight
BMI 18.5–24.9 — Normal weight
BMI 25–29.9 — Overweight
BMI ≥ 30 — Obesity

Source: CDC – About Adult BMI

Why does Calorium use HealthKit?

Calorium integrates with Apple HealthKit to provide more accurate and personalized calorie tracking. HealthKit collects real-time data from your Apple Watch and other compatible devices, including:

Active energy burned during workouts
Steps taken and walking distance
Heart rate and other fitness metrics

By syncing with HealthKit, Calorium can automatically add calories burned to your daily total and include this data in your global health journal. This helps you stay on track with your goals without needing to enter everything manually.

You remain in full control of your data — Calorium only accesses the data you explicitly allow.

How can I improve the accuracy when scanning a meal?

To improve food recognition accuracy when using the camera in Calorium, follow these tips:

📸 Hold your phone directly above the meal at a 90° angle
📏 Maintain a consistent distance — about 50 cm (20 inches) from the plate
💡 Make sure the lighting is bright and even (avoid shadows)
🍽 Place the food on a clear, non-distracting background (like a plain plate)

These small adjustments significantly increase the precision of AI-based food recognition.

Is it safe to use these formulas without a doctor?

These calculations are general estimates and should not replace professional medical advice. If you have any medical conditions or concerns, please consult a healthcare provider.