BMR & Metabolism: How Many Calories Do You Burn at Rest?

What Is BMR?

Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest just to keep you alive. This includes breathing, circulating blood, cell production, and maintaining body temperature. BMR typically accounts for 60-75% of your total daily calorie burn.

Factors Affecting BMR

Age: BMR decreases by about 1-2% per decade after age 20. Body composition: Muscle tissue burns more calories at rest than fat tissue. Sex: Men typically have higher BMRs due to greater muscle mass. Height and weight: Larger bodies require more energy. Genetics: Some variation in metabolic rate is inherited.

BMR vs TDEE

Your Total Daily Energy Expenditure (TDEE) includes BMR plus the calories burned through daily activity and exercise. TDEE is what you should use for calorie planning. Multiply your BMR by an activity factor: sedentary (1.2), lightly active (1.375), moderately active (1.55), very active (1.725), or extremely active (1.9).

Can You Boost Your Metabolism?

Strength training is the most effective way to increase BMR because it builds muscle tissue. Getting adequate sleep (7-9 hours) supports hormonal balance. Eating enough protein has a higher thermic effect, meaning your body burns more calories digesting it. Crash diets lower your BMR, which is one reason extreme calorie restriction backfires long-term.

Using Your BMR

Knowing your BMR helps you set realistic calorie targets. Never eat below your BMR for extended periods, as this can slow your metabolism and cause nutrient deficiencies.