What is TDEE?
Total Daily Energy Expenditure (TDEE) represents the total number of calories your body burns in a day. It is the sum of your Basal Metabolic Rate (BMR), the Thermic Effect of Food (TEF - approximately 10% of caloric intake), Non-Exercise Activity Thermogenesis (NEAT - calories from daily non-exercise movement), and Exercise Activity Thermogenesis (EAT - calories from planned exercise). According to research published in the Journal of the Academy of Nutrition and Dietetics, accurate TDEE estimation is the foundation of effective nutrition planning.
The Mifflin-St Jeor Equation
The Mifflin-St Jeor equation, published in 1990, is considered the gold standard for estimating BMR by the American Dietetic Association. It was developed by studying a diverse population and is more accurate than older formulas like Harris-Benedict (1919). The formula accounts for weight, height, age, and sex. For men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age(years) + 5. For women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age(years) − 161.
Understanding Calorie Balance
Weight management follows the principle of energy balance. To lose weight, you need to consume fewer calories than you burn (caloric deficit). To gain weight, you need to consume more (caloric surplus). A deficit of 500 kcal/day results in approximately 0.5 kg of fat loss per week, since 1 kg of body fat stores roughly 7,700 kcal. However, the World Health Organization recommends that weight loss should not exceed 0.5–1 kg per week for sustainable, healthy results. Extreme calorie restriction can be counterproductive and harmful.