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Many doctors consider metabolic testing a key component to evaluating and treating overweight and obese patients throughout the weight-loss process. The vital information derived from a test allows a doctor to monitor and diagnose weight-loss plateaus while providing an “informational and motivational” guide to teach patients about their body and their ability to lose weight. 

Below are some resources to help you learn more about RMR testing with KORR’s ReeVue Metabolic Analyzer. You can also schedule a 15-minute video call or join our email list.

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.

Conducting a Test on ReeVue™  is as simple as 1, 2, 3…

  1. Turn on the ReeVue ™ and wait while it automatically calibrates. The machine will indicate when calibration is complete. 
  2. Expand KORR’s disposable breathing hose and connect it to the machine. Have the patient place the nose clip on their nose and the mouthpiece in their mouth. 
  3. Tell the patient to relax and breathe normally. After approximately 10 minutes, the machine will end the test. The results can then be printed 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
    • Hyper-metabolic 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.


The ReeVue has a simple user interface that assists the operator from start to finish.  No training or certification is required.  It does not require a computer or software, and even the printer is optional.  Everything you need is at your fingertips!

Self Calibrating

Adjustments for barometric pressure, temperature, and humidity are key to an accurate VO2 measurement.  The ReeVue measures these parameters during each routine calibration cycle, then automatically compensates to standard (STPD) conditions.


The ReeVue performs an oxygen uptake test, which is CPT code #94690.


Other Indirect Calorimeters require the patient to draw both their inhalation and exhalation through the measurement device located at the patient’s mouth.  The air they breathe in will pass through the same mechanism as countless patients before them.  KORR uses a one-way valve in the disposable MetaBreather mouthpiece.  This draws in fresh room air with each inspiratory breath and eliminates concerns about cross contamination.  The disposable is thrown away and there is no need to clean equipment between each patient.

Direct Oxygen Measurement

ReeVue by KORR directly measures the concentration of oxygen breathed out by each patient.  The patient merely breathes through a simple mouthpiece as all the exhaled air is collected and analyzed.  Because there is a direct correlation between oxygen consumed and calories burned (4.813 calories for every milliliter of oxygen consumed), an accurate measurement of oxygen consumption is an effective measurement of calorie consumption.

Mixing chamber Technology

A mixing chamber is considered the “Gold Standard” for Indirect Calorimetry (more commonly referred to as a Metabolic Measurement.) In the past, this system has been complicated and expensive, making it only practical for ICU’s and research departments. KORR advancements in technology make this method feasible for the typical practitioner.

Indirect calorimetry is CPT coded and is covered by Medicare and most insurance providers.  If you have any questions about insurance coverage, contact insurance providers directly.

For more information about reimbursement, click here.

ReeVue studied by Georgia State University –
Found to be Valid and Reliable.

Dr Sarah Henes, PhD and her colleagues at the Georgia State University Department of Nutrition have published a study indicating the KORR ReeVue is reliable and valid for assessing Resting Metabolic Rate (RMR) when compared with the CosMed Quark, a traditional metabolic cart 3-5 times more expensive. The study specifically tests ReeVue’s reliability and validity for assessing RMR in an overweight and obese adolescent population.

Highlights from the discussion include:

  • This study demonstrates that there was no significant difference in measured RMR (kcal/d) when comparing the portable indirect calorimeter with a traditional indirect calorimeter. Data indicate that the portable indirect calorimeter used in this study (ReeVue) is both reliable and valid compared with the traditional indirect calorimeter.
  • It demonstrates a clinically relevant example of comparing predicted and measured RMR in 2 female individuals who “look” the same based on sex, height, weight, and age but are, in fact, very different. While the predictive equations would estimate each patient’s RMR as essentially the same, actual measured RMR was approximately 200-390 kcal/d lower in one participant and 155-270 kcal/d higher in the other participant.  The clinical importance of this is paramount and indicates that more accurate nutrition recommendations may be determined by measuring an individual’s RMR rather than estimating RMR using predictive equations in overweight and obese adolescents.
  • Ultimately, more accurate nutrition and weight management recommendations on an individual basis may lead to more successful outcomes when working with overweight and obese adolescent patients in the clinical setting.

To read more, click here.

Why test RMR?

Using RMR to treat plateaus

ReeVue Testimonials

How to perform an RMR test

Want even more information? Join our email list to receive weekly emails with case studies, webinars, research articles and more!

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