Metabolism and metabolic rate

Do you know someone who seems to eat much much more than you do, yet that person never seems to gain weight? But you appear to survive on very little and still struggle to shed those extra kilograms? Sound familiar?

Well it often comes back to Metabolic Rate - how fast your body operates and how much fuel (kilojoules or calories) it needs.

Your Resting Energy Expenditure and Metabolic Rate is unique to you - no one has the same metabolism as you have. A slow metabolism may explain why it is hard for you to lose weight and the only way to check that is to have your Metabolic Rate measured.

The test takes up to 60 minutes and needs you to lay down, relax and breathe normally. The biggest challenge is not to fall asleep! No exercise or treadmill or blood tests are involved.

Without any lingering doubt, you will discover exactly how fast or slow your metabolism is and how many calories (kilojoules) your body needs at rest. From there, your dietitian and exercise expert can establish a great plan to get your health and weight into better shape.

Metabolic rate testing equipment is highly sensitive. The equipment I use is validated in scientific studies and is of research quality but I are no longer taking bookings for this test due to clinic changes. So where else can you get the test conducted?

Metabolic rate tests are also conducted by Respiratory Laboratories - the same ones that test for sleep apnoea, asthma and other lung or breathing issues. You possibly have a specialist clinic in your area.

A few exercise physiologists and dietitians also have equipment that measures metabolic rate.

If you are planning to get tested, be sure to ask a few key questions when you book in for the test at these centres. There are a load of sham fake metabolic rate tests on offer.

Ask these questions before you book:

  1. Does the test actually measure Respiratory Quotient (RQ) or is an assumed RQ used? Whilst you don't need to know what RQ is all about, it is important that their equipment measures RQ and does not use an assumed RQ.
  2. Does the test measure both oxygen and carbon dioxide levels? If it doesn't do both, then it can't be measuring the RQ!
  3. How do they know when to stop the test? They should indicate that the machine or data set tells them when steady state has been achieved. It should not be automatic to always finish the test after 10-15 minutes.
  4. Do I have to do anything to prepare for the test? Yes you do! if they say you can do the test straight away or without any preparation, don't have it done! There are strict protocols in place to help ensure a valid test is run. This is a bit like having to fast for certain blood tests - if you don't fast, the result is wrong. Same with a metabolic rate test - if you enter the test incorrectly, the results will be wrong. At a minimum, you need to fast, not exercise, and have no caffeine or other stimulants. The people running the test should give you strict instructions.
  5. Do I lie down or sit up to do the test? You should lie down (or at least be in a recliner chair that is lowered back towards lying position) to do the test as this is the most relaxed position. It best reflects resting position. Having the test run in an upright sitting position is invalid.

Please note that this test is not to be confused with a body composition test (BIA or bio-impedance assessment or Dexa scan) which measures the amount of fat and lean tissue stored in your body. Some gyms and weight loss centres tell you that this BIA/Dexa gear works out your metabolic rate but the truth is these machines use a calculator, a theoretical 'average fit' mathematical formula, to guesstimate your rate. They measure your body composition (fat and muscle), not your metabolism.

Basal Metabolic Rate (BMR) is often confused with the term Resting Energy Expenditure (REE).

Speak with your dietitian or exercise expert about what these terms mean for you.