What is Resting Metabolic Rate (RMR)?
Metabolism, quite simply, is the conversion of food to energy. Metabolic rate is a measure of how much food, or fat, is converted to energy in a day. Resting metabolic rate (RMR) is the measurement of how much food, or energy, is required to maintain basic body functions such as heartbeat, breathing, and maintenance of body heat while you are in a state of rest. That energy is expressed in calories per day. So, an RMR test shows how many calories you burn at rest, doing nothing more than sitting in a chair.
Indirect calorimetry (a measurement of metabolic rate) relies on the fact that burning 1 calorie (Kilocalorie) requires 208.06 milliliters of oxygen. Because of this very direct relationship between caloric burn and oxygen consumed, measurements of oxygen uptake (VO2) and caloric burn rate are virtually interchangeable.
Oxygen uptake requires a precise measurement of the volume of expired air and of the concentrations of oxygen in the inspired and expired air. The process requires that all of the air a person breathes out be collected and analyzed while they rest quietly. The KORR™ indirect calorimeters contain a precision air flow sensor that measures the volume of expired air, and an oxygen sensor that measures the concentration of oxygen. Once the factors of humidity, temperature and relative humidity are accounted for, the KORR™ instrument provides the most accurate results available in a compact metabolic analyzer.
It is desirable to measure a person’s metabolic rate at a true resting level. To ensure one is at rest, we recommend the following preparation:
- Avoid eating a meal 4 hours before the test.
- Avoid exercising on the day of testing.
- If possible, avoid the use of stimulants such as caffeine prior to testing.
- During the test it will be important to get into a comfortable position and relax as much as possible.
- Keep lips sealed lightly around the mouthpiece. It is important that all the air breathed out is analyzed by the MetaCheck™.
Why Test RMR to Treat Obesity
Proof of “normal” metabolism
Most overweight people are convinced they have a slow metabolism. The truth is that statistically, most overweight and obese individuals have average or higher than average metabolic rates. Taking a measurement removes this excuse. Seeing that their bodies can indeed burn calories can be very encouraging and motivating.
Stabilize weight loss
Regardless of the method used to lose weight, a patient’s RMR will decrease after weight loss. The decrease is actually below the level predicted by fat-free mass (FFM). Although the cause is unclear, it appears that in most cases, if a patient can maintain his new weight for 6 months, his RMR will eventually rise to the expected level. Pinpointing the precise number of calories necessary to maintain is key to surviving this crucial period.
Pinpoint caloric weight loss zone
When restricting calories, knowing a baseline RMR is invaluable. KORR Metabolic Analyzers calculate a “weight loss zone” for 1 ½ pound a week weight loss, or practitioners can use the RMR to calculate a caloric goal unique for their patients.
Detection and Diagnosis of hypo-metabolism
In cases where a patient has a clinically low metabolic rate, further diagnosis and treatment by a physician will be required before successful weight loss can be achieved.
Assess the effect of weight loss treatment on metabolism
Once calories are restricted, medications are introduced, or an exercise plan has been implemented, the human body will respond. This is especially true of significant interventions, such as bariatric surgery. The caloric goals of a dietary plan will rarely sustain a patient throughout an entire weight loss regimen. The result is the dreaded “plateau.” Periodic assessment of RMR will show the effects of the treatments and allow adjustments to the caloric goals.
If you do have insurance and want to determine your coverage for the testing, the CPT Code for the testing is 94690. You can use this information to contact your insurer and inquire about the benefits for this service that are outlined in your plan.
If you do not have insurance, or if the service is applied to your deductible, the cost of the test at Family Care is $55.