Browse below to learn more about Resting Metabolic Rate
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™.
Conduct a Test
- Turn on the MetaCheck ™ and wait while it automatically calibrates. The machine will indicate when calibration is complete. It is important that no hose or filter be attached during calibration.
- Expand the MetaBreather™ hose to its full length (5 feet) and connect it to the MetaCheck™. Be sure to use only a KORR™ manufactured MetaBreather™, as use of any other breathing device will not insure accuracy and will void your KORR™ factory warranty.
- Have the patient place the nose clip on his nose and the mouthpiece in his mouth, using his lips to seal around the edges. The patient should be relaxed and breathe normally.
- After approximately 10 minutes, the MetaCheck™ will end the test and prompt the tester to enter in patient data to compare patient results to averages. The results can then be printed out.
The Print Out
Click the button below to view/download the sample report print out
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.
Why Test RMR for Nutritional Assessment
- Proper nutritional care is VITAL for the hospitalized patient. Studies show that hospital stays are reduced an average of 60% when nutritional status is evaluated and needs are met.
- The formulas that predict caloric needs for nutritional assessment (Harris Benedict, Miffin, etc) are inadequate for certain populations, especially sick or hospitalized patients. RMR is recommended for the following populations:All patients receiving parental or enteral nutrition
- Hypermetabolic patients (burns, trauma, sepsis, head injury)
- Starvation-adapted or malnourished patients
- Extremely obese patients (>=200% of ideal body weight)
- Patients with non-healing wounds
- Patients with abnormal body composition (multiple sclerosis, cerebral palsy, cystic fibrosis, spinal cord injury, amputations).
- Patients who can benefit from education about appropriate calorie intake.
Below are some frequently asked questions about RMR. If you have a question that is not anwered below, please contact us at 1-800-895-4048 or fill out our contact form on our contact page.
- Watch Video on implementing ReeVue into your practice
- Implementing RMR testing with MetaCheck or CardioCoach Plus
Additional researchers at the University of Pennsylvania noted that the obese have Resting Energy Expenditures that are particularly difficult to predict. Their findings read, “Caloric prescription for weight reduction must be tailored to individuals rather than recommending the same caloric intake to persons with varying metabolic rates.” (Foster GD, et al, Metabolism. 1988 May;37(5):467-72.)
If calorie intake is decreased, most studies indicate that strength training can reduce the loss of fat-free mass (lean muscle) but not prevent the decline in RMR that invariably comes with dieting.(Geliebter)
But studies are difficult to compare and summarize due to the many differences in the resistance training protocols and experimental designs. Researchers at West Virginia University found success maintaining RMR through intensive high volume resistance training designed to affect more muscle groups and by increasing protein intake to 80 g/day. (Bryner)
Economics are an additional concern related to TPN. Its significant cost must be considered when contemplating the value of determining a patient’s precise caloric need through RMR testing. A study by Foster measured REE in 100 TPN patients and compared those results to the published guidelines for determining TPN needs. Following those published guidelines instead of the actual REE resulted in the administration of 6947 excess liters of TPN per year! (Foster, Flancbaum)