Basal Metabolic Rate Human Biology 11

What Is Your BMR? Your BMR measures the minimum calorie requirement your body needs to stay alive in a resting state It is the amount of calories your body would need if you were to stay in bed all day

How Many Calories Is This? About 70% of your calorie intake is responsible for just supplying your BMR You need calories to: –Pump your heart –Breathe –Control your body temperature –Any many other things

Do We All Have The Same BMR? We all have different BMR and there are many things that will affect what that rate is Your BMR is the largest factor in determining your overall metabolic rate (how your body burns calories)

Genetics Some people are born with slower metabolisms than others Some people are born with faster metabolisms than others

Gender Men have a greater muscle mass and a lower body fat percentage (10-15% higher BMR than womem) The higher your muscle mass, the higher your metabolism

Age Your BMR will reduce as you age After 20 years of age, your BMR drops about 2% every year

Weight The more you weigh, the higher your BMR The BMR of an obese woman is 25% higher than a woman of an appropriate weight

Body Surface Area The greater your body surface area, the higher your BMR Tall, thin people have higher BMRs

Body Fat Percentage The lower your body fat percentage, the higher your BMR

Diet If you reduce your calorie intake suddenly, your BMR can drop by 30% Your body wants to ensure that it is always has the calories it needs to survive, so cutting calories quickly will switch your body into a “survival” mode

Body Temperature For every 1 degree increase in your body temperature, your BMR increases by approximately 14% Chemical reactions occur faster in your body at higher temperatures You burn a lot more calories while you are sick or have fever

External Temperature Exposure to cold temperatures will increase your BMR Prolonged exposure to heat will also increase your BMR

Glands Your thyroid gland (butterfly-shaped gland in your neck) is responsible for making thyroxin The more thyroxin produced, the higher your BMR

Exercise Exercise helps to build lean muscle tissue The more lean muscle tissue, the higher your BMR This means you will burn more calories – even when you are sleeping!