RMR and Nutrition Assessment: Why is it necessary to measure oxygen consumption?
Most healthcare professionals recognize that resting metabolic rate is impacted by unique characteristics such as age, obesity, body composition (muscle versus fat), recent weight changes and medications.
When assessing a client’s nutritional needs, knowledge of RMR is critically important for determining the patient’s unique nutritional needs.
In outpatient settings, it is appropriate to re-measure every ± 10% weight change to ensure continued weight management success.
Factors Influencing Oxygen Consumption and RMR
- Body weight: A larger person will typically have a higher oxygen consumption because the body must provide energy to support the extra body mass.
- Body composition: Muscle requires more oxygen than fat, even at rest. People with a higher percentage of muscle will usually have a higher RMR. Exercise, especially resistance training, can increase lean tissue, and therefore increase RMR.
- Age: RMR declines naturally in adults at a rate of about 3% per decade after age 30. However, this decrease is primarily a result of muscle loss.
- Gender: Men normally have a higher oxygen consumption than women, partly because they tend to have a lower percent body fat than women.
- Hormones: Certain hormones can increase or decrease oxygen consumption. The thyroid gland has the most marked effect on metabolism.
- Stress: Stress, trauma, burns, infections, and sepsis promote a hypermetabolic response. The severity of the surgical procedure or the trauma influences the metabolic response.
- Medications: Medications can increase or decrease oxygen consumption depending on the mechanism of action.
- Genetics: There are many genetic factors that may increase or decrease resting metabolic rate.
To find out more about you can scientifically measure your clients RMR with the BodyGem indirect calorimeter, click on BodyGem