BMR explained: what it is and how to increase it
Original EKCal illustration.
When people say "I have a slow metabolism," what they're often describing — without knowing the term — is their Basal Metabolic Rate. Understanding your BMR is the first step to working with your body instead of against it.
What is BMR?
Basal Metabolic Rate (BMR) is the calories your body burns at complete rest — the minimum energy needed to keep your heart beating, lungs breathing, brain functioning, and cells regenerating. BMR represents roughly 60–70% of your total daily calorie burn, making it the single largest contributor to your TDEE.
How is BMR calculated?
The most accurate widely-used formula is the Mifflin-St Jeor equation:
- Men: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
- Women: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
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Calculate my BMR →What affects your BMR?
- Muscle mass — Muscle burns calories at rest; fat burns far fewer. Building muscle is the most effective strategy for permanently raising BMR.
- Age — BMR naturally declines with age as muscle mass is lost. Resistance training significantly slows this.
- Body size — Larger bodies burn more calories at rest simply because there is more tissue to maintain.
- Hormones — Thyroid hormones directly regulate metabolic rate. Hypothyroidism can meaningfully reduce BMR.
Science-backed ways to raise your BMR
Build muscle through resistance training
Each kilogram of muscle burns roughly 13 kcal per day at rest, versus ~4.5 kcal for fat. Two to four resistance sessions per week compounds into a meaningful metabolic difference over months.
Eat enough protein
Protein has a thermic effect of ~25% — your body burns roughly a quarter of the calories just digesting it. Consistently high protein intake provides a small but real metabolic boost.
Avoid very low calorie diets
Severe restriction causes metabolic adaptation — BMR can drop 10–15% on very low calorie diets. This is the main reason crash diets don't work long-term.
Prioritise sleep
Chronic sleep deprivation disrupts hormones that regulate metabolism, hunger, and fat storage. Seven to nine hours per night supports healthy metabolic function.
Key takeaways
- BMR is the calories your body burns at complete rest — 60–70% of total daily burn.
- The main drivers are muscle mass, age, body size, and hormones.
- Resistance training is the most effective way to raise BMR long-term.
- Adequate protein and avoiding extreme deficits protects your metabolic rate.
- Calculate your BMR as the first step to setting any calorie target.
What can and cannot change BMR
Body size and lean mass strongly influence resting energy needs. Building muscle can raise daily energy use, but the change is usually gradual—not a licence to eat without limits. Fever, thyroid disease, pregnancy, growth, aging and some medications can also affect energy needs.
Most “metabolism boosters” have a small or temporary effect. The practical levers are maintaining muscle, moving more across the day, sleeping adequately and avoiding repeated extreme diets that are difficult to sustain.
Use BMR correctly
BMR is not your daily calorie allowance. You also use energy for digestion, walking, work, exercise and every other activity. Multiply BMR by an activity estimate to get TDEE, then compare that estimate with your real weight trend.
A simple way to put this into practice
- Choose one measurable behavior for the next seven days.
- Keep the rest of your routine reasonably stable.
- Review weekly averages rather than one-day results.
- Adjust only after you have enough information.
Sources and evidence base
- National Institute of Diabetes and Digestive and Kidney Diseases — Weight Management
- Centers for Disease Control and Prevention — Healthy Weight and Growth
- Physical Activity Guidelines for Americans
- USDA FoodData Central
References support general principles; they do not make EKCal a substitute for clinical care. See our Editorial Policy and Sources & Methodology.