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Metabolic Testing

Metabolic Testing

 

What Is Metabolism?
Metabolism is the biochemical process of combining nutrients with oxygen to release the energy our bodies need to function. Metabolism is typically measured in kilocalories or, more commonly, calories. Total metabolic rate represents the calories needed for maintaining body functions, daily activity (occupational and lifestyle), and the energy cost of exercise or planned activity.

 

What is RMR?
Resting metabolic rate (RMR) represents the calories the body burns to maintain vital body functions (heart rate, brain function, breathing). In simple terms, it is the number of calories a person would burn if they were awake, but at rest all day. RMR can represent up to 75% of a person’s total metabolism if they are inactive or lead a sedentary lifestyle.

Why is it necessary to measure RMR?
Since RMR accounts for up to 75% of the total calories we need each day, it’s a critical piece of information to appropriately establish daily calorie needs, whether we’re trying to lose or maintain weight. Most healthcare and fitness professionals recognize that metabolism is impacted by a variety of characteristics such as fever, illness, high fitness, obesity, active weight loss, etc. When managing a client or patient’s nutritional needs and calorie requirements, knowledge of RMR is critically important. Traditionally, healthcare professionals, who have not had access to measurement technology, have relied on estimates of RMR. Because metabolism is different among individuals, estimating can lead to errors, and inaccurate calorie budgets. As a result of these estimates, individuals can be both over- or under-eating, and not be successful in reaching their personal goals. As technology advances, professionals must reassess their practices. The most accurate assessment of caloric needs is by measuring oxygen consumption and determining individual metabolism.

How do you measure RMR?
Metabolic rate is traditionally assessed using either direct or indirect calorimetry. Direct calorimetry requires the precise measure of heat output using a large, expensive and technically complex whole body calorimeter. Indirect calorimetry determines metabolic rate from the oxygen consumption of an individual. Oxygen consumption measurements are typically done with a medical device called a metabolic cart. These devices are relatively expensive, $20,000 - $50,000, require technical expertise to operate, and require routine maintenance and calibration. Over the past 10 years, HealtheTech has harnessed revolutionary new technology to develop the MedGem, which is a handheld device that can measure oxygen consumption and determine an individual’s caloric needs. Measuring oxygen consumption, rather than using population-based predictive equations, allows health and fitness professionals to make the most accurate decisions for their clients. With a simple breath test of 10 minutes or less, an individual can now have their unique metabolism measured, for determination of a personalized calorie budget.

 



Weight Loss
When individuals lose weight, their metabolism may decrease. This should not be alarming because the decrease
 in metabolism is a result of tissue loss (fat and muscle). Weight loss ideally results in proportionately more fat
 loss and some muscle loss.
Strength training during weight loss can lessen the muscle loss, but most people will experience some muscle loss.
 During weight loss, the body may also lower metabolism in response to a lower calorie intake. Most people
experience this change in metabolism without realizing it. Weight loss may be easy for the first few pounds and
 then weight loss becomes more difficult and may even plateau. At a lower metabolism, an individual
must adjust dietary intake or increase activity through exercise to lose additional weight. The good news is that
after weight loss, metabolism may increase slightly once the individual’s weight is stable. During weight loss, it is
helpful to monitor changes in metabolism and make necessary adjustments to food intake for successful
 weight management.



 

 

The MedGem device is a handheld, portable tool that measures oxygen consumption (VO2) to determine resting metabolic rate (RMR). Accurate determination of
calorie budget based on unique RMR plays a role in the care of individuals with diabetes, heart disease, high blood pressure and obesity. RMR also plays a vital role
 in the treatment of conditions with significant risk of malnutrition such as cancer, burns, trauma and HIV.

Nutrition monitoring plays a vital role in the care of patients with diabetes, heart disease, high blood pressure, and obesity, as well as conditions that place patients
 at risk for malnutrition, such as cancer, burns, trauma, infection, obstructive lung disease,


 

 




 

 

 

 

RMR is calculated using the Weir equation. The Weir equation and a constant RQ value of 0.85 (RMR=6.931d X V02) is used to convert V02
to RMR. Weir, J.B., New Methods of Calculating Metabolic Rate with Special Reference to Protein Metabolism. J Physiol. 1949; 109:1-9.


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