Resting Metabolic Rate

Your Resting Metabolic Rate (RMR) (kcal/day) represents the minimum energy your body needs to support its basic physiological functions, including heartbeat, breathing, maintaining body temperature, and all of the numerous biochemical reactions required to keep you alive. In essence, it is the amount of energy the body uses at rest.

How is RMR Calculated?

Due to the strict protocol and technical difficulties associated with obtaining an accurate measurement of RMR, prediction equations have been developed to estimate RMR based on parameters more easily measured. Research studies indicate that prediction equations which account for both fat and fat-free mass provide the most accurate estimates of RMR. Therefore, the equation of Nelson et al (American Journal of Nutrition 56:848-56, 1992), which includes accurately measured fat and fat-free mass as predictors, provides a reliable and accurate assessment of your RMR. This equation is also useful in tracking RMR changes that occur with a change in either fat or fat-free mass.

Why Do I Need To Know My RMR?

Most of us understand that weight management depends upon the energy balance equation: the amount of energy you put into your body (your caloric intake) versus the amount of energy you expend (your TEE). The way to lose body fat is to maintain a negative energy balance. This is accomplished by reducing caloric intake, increasing TEE or, preferably, a combination of both. Your RMR is dependent primarily on the fat-free part of your body, and accounts for the vast majority of your TEE. So to improve your overall fitness, it is critical to know your RMR.

 

• • Changes in your RMR can be used to influence changes in your body composition. If you lose body fat and replace it with muscle, you should see a steady increase in your RMR. Having your RMR monitored throughout a weight management program can help you track improvements in your muscle mass, thus optimizing your fat loss and fitness/ nutrition program safety.
  • RMR can be used to provide an estimate of your TEE, which can help manage your daily caloric intake. While RMR is generally 65% of your TEE, the level of your physical activity can add significant variability to the actual percentage. For this reason, your Daily Activity Level should also be taken into account when determining your TEE. (Sedentary, Low Active, Active, Very Active)