Question:

Is there a more sophisticated equation used to calculate one’s BMR? Or is it only weight/height?

-Matt O. 

Answer:

In fact, there are! Most equations include gender and age in addition to height and weight.

“Basal metabolic rate is the amount of energy that is required to maintain basic body functions such as heartbeat, breathing and maintenance of body heat while you are asleep.”

One of the most popular equations to calculate an adult’s basal metabolic rate is the Harris-Benedict, which is as follows:

• * Women: 655 + (4.35 x weight in pounds) + (4.7 x height in inches) – (4.68 x age in years)
• * Men: 66.5 + (6.23 x weight in pounds) + (12.7 x height in inches) – (6.78 x age in years)

Used often in the medical and weight loss fields because of its accuracy, and recommended by the Academy of Nutrition and Dietetics is the Mifflin St. Jeor for resting (awake/alert) metabolic rate:

• * Women: (10 x weight in kg) + (6.25 x height in cm) – (5 x age in years) – 161
• * Men: (10 x weight in kg) + (6.25 x height in cm) – (5 x age in years) + 5

As any equation is actually an estimation of your needs, you might want to try both and obtain a range that your true BMR probably falls within. Neither of the above take into consideration lean mass versus fat mass, so they aren’t practical for extremely muscled or morbidly obese individuals. For teens, the Schofield method (previously used by the World Health Organization and the US government to formulate the RDAs) has different equations for various age groups.

Measurements of metabolism are usually only done in research laboratory settings but might be conducted by endocrinology specialists. If you are sustaining your weight by eating fewer than 1200 calories per day, you should see your primary care physician.

– Debbie J., MS, RD

This article should not replace any exercise program or restrictions, any dietary supplements or restrictions, or any other medical recommendations from your primary care physician. Before starting any exercise program or diet, make sure it is approved by your doctor.