Frequently asked questions
What is the difference between TDEE and BMR?
BMR (Basal Metabolic Rate) is the calories your body burns at complete rest just to maintain vital functions (breathing, circulation, cell repair). TDEE adds all your daily activity on top of that, including exercise, walking, and even digesting food. TDEE is always higher than BMR.
Which formula is more accurate, Mifflin-St Jeor or Harris-Benedict?
A 2005 review of predictive equations found Mifflin-St Jeor is the most accurate for most adults, predicting within 10% of measured values for 82% of people. Harris-Benedict tends to overestimate slightly. Both are estimates; the best formula is the one whose results match your real-world weight trend.
How do I choose my activity level?
Be honest and conservative. Most office workers who exercise 3–4 times/week are 'Moderately active,' not 'Active.' 'Active' means intense exercise 6–7 days/week plus a physically demanding job or daily heavy training. Overestimating activity is the most common error.
Why is my TDEE different from what my fitness tracker shows?
Wrist-based trackers overestimate calorie burn by 20–90% depending on the brand and activity. TDEE equations overestimate by around 10% for most people. If weight isn't changing as expected, trust your real-world trend over either estimate and adjust by 200–300 kcal.
Can I use TDEE to lose weight?
Yes. Eat 500 kcal below your TDEE to lose roughly 0.5 kg (1 lb) per week. A deficit of 300–500 kcal is sustainable for most people. Going below 1000 kcal deficit risks muscle loss, fatigue, and metabolic adaptation. Track for 2–3 weeks and adjust based on actual weight change.
Does TDEE change as I lose or gain weight?
Yes. As you lose weight, your BMR drops (less tissue to maintain) and TDEE decreases. Recalculate every 5–10 kg of change, or monthly if actively dieting. This is why weight loss slows over time and periodic recalculation matters.
Why do men burn more calories than women?
On average, men have more muscle mass, larger organs, and higher testosterone, all of which increase metabolic rate. A typical 75 kg man has a BMR 200–400 kcal higher than a 60 kg woman. This difference is accounted for by the sex variable in both equations.