Metabolic Age Tests- to be taken with a pinch of salt.

Since we saw the Taoiseach have his metabolic age test on Operation Transformation recently, we have become a nation OBSESSED!

If you didn't see the clip, Leo aged 40 was told he has a metabolic age of 53, and he was not happy about it, saying afterwards "kinda wondering about the science".

Our Taoiseach is right to question the science behind it.

First of all, let's talk about what the test involves. The test calculates your basal metabolic rate (BMR). This is the amount of energy your body requires to function, without movement/activity- E.G. breathing, digestion, circulating blood etc. It measures BMR by assessing the amount of fat mass vs. lean muscle mass- based on the knowledge that the more muscle mass we have, the higher our BMR will be.

The BMR calculated from the test is compared to the average for people your age, and based on how yours compares to theirs, you'll be assigned to the most appropriate age. Of course, if your metabolic age is higher it means your BMR is low and if it is lower than your actual age, it means your BMR is high.

And your result is interpreted as low metabolic age=good/healthy, high metabolic age=bad/unhealthy.

So all that makes sense & sounds reasonable enough, but there are some issues with using metabolic age as a marker of health.

The test bases health on only body composition, but health is more than that. What about other markers like blood pressure & blood glucose? What about lifestyle factors like sleep quality, stress levels and nutrition? What about genetics and family history? Sure, BMR is important, and it is interesting to learn about your own, but is not the only or best way to evaluate health.

The accuracy of the test is highly variable. If you got the test done on different days, you would get different results, and if you went to different locations/used different machines you would get different results.

Your hydration, place in your menstrual cycle, activity levels etc all change regularly and are factors that can impact results.

In terms of the machines used, they must be accurately calibrated and re-calibrated regularly to ensure they are producing accurate readings. Testing of this is often something that is not carried out regularly, particularly in very busy healthcare settings.

Results can be misinterpreted if not read and assessed by someone who understands them. Many are using the metabolic age test results to encourage people to improve their diet or increase their activity levels- which is great. BUT, you should not make drastic changes to your diet without talking to a qualified nutrition professional.

And I strongly discourage people reducing their energy intake to their BMR level.

I think the media coverage of metabolic age testing has started an interesting conversation around our health as we age, and how what we do now can affect our health down the line, and it is great to see & hear more conversations about that.

BUT we have to remember that this test is not the only indicator of health and it is prone to high variability. It is an estimate, and it views health from one perspective (body composition).

Ultimately, we should all try to look after ourselves a bit more, not so we can have a metabolic age of 20, but so we can live in good health for as long as possible!

If the test motivates you to look after your health then great- but remember the aim is health maintenance, not rock hard abs or a "beach body".

When it comes to realistic health small changes add up.

Here are some ideas to get you started:

  • Have an extra portion of fruit or veg every day.

  • Try including wholegrain bread, pasta and rice regularly.

  • Go for a 10 minute walk every day on your lunch break.

  • Park at the back of the car park so you have further to walk to the car.

  • Take the stairs more.

  • Remember to stretch your muscles, warm up and cool down when you move.

  • Get into a sleep routine and aim for 6-8 hours every night.

  • Get a re-useable water bottle and aim to drink 1.5L every day.

And when it comes to nutrition, remember that variety is key and all foods can fit in a healthy diet (so long as you enjoy them!).

If you've had your metabolic age tested, what did you think of your results??

(you don't ave to share numbers, just your experiences and thoughts!)

Lots of love,

Little O x

#metabolicage #metabolism #BMR #basalmetabolicage #ageing #health #nutrition #nutritionist #localnutritionist

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Protecting the public and promoting high standards in evidence-based science and professional practice of nutrition.

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