BMR Calculator / Formula – Harris Benedict

BMR calculator formulas such as the Harris Benedict formula (BMR based on total body weight) and Katch-McArdle formula (BMR based on lean body weight) do not take into consideration the following factors which affect your clients metabolic rate:

  • Thyroid issues can speed up or slow down metabolism
  • Certain hormones can increase or decrease metabolism.
  • Certain supplements can increase or decrease metabolism.
  • Pharmaceuticals – Prescription and OTC drugs can increase or decrease RMR

Measured RMR is superior to industry standard estimation equations, because your clients actual metabolic rate can vary greatly.

Knowing your clients metabolism matters because consuming 300 calories too much
every day can add up to 30 pounds in a year.

If they don’t eat enough calories, their body will work against them to preserve its long-term energy source, which is fat; and it may actually slow down their metabolism.

For the best care, the American Dietetics Association recommends using Indirect calorimetry to measure RMR for the most accurate assessment of nutritional needs.

Instead of estimating BMR and daily calorie intake, you can scientifically measure a clients Resting Metabolic Rate – RMR with the BodyGem indirect calorimeter.

In 5-10 minutes, you can take a snapshot of your clients Metabolic Fingerprint.

The metabolic effects of thyroid and hormone issues, body composition, and other variables, are all captured during a BodyGem measurement.

Then you can use your clients unique resting metabolic rate as the foundation of your recommendations for their daily calorie intake.


As a personal trainer, using the BodyGem device on my clients has opened their eyes to the importance of good nutrition. Most were underestimating their calories on a daily basis. What a great tool!

Heather Stevens
Athletics Director, Colorado Athletic Club

To get more information:

  • Click on BodyGem
  • Call me directly at 720-431-1461
  • Or leave a voicemail at 1-866-285-8296 and I’ll call you back

I wish you the best of health!

David Wilcoxson

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