BMI Survey

[Psamathe]

(If you don't know, an online calculator to work it out - you need your height and weight http://www.nhs.uk/tools/pages/healthyweightcalculator.aspx).

Purpose of the survey is that it struck me from another thread that the build of people would probably vary based on their activity levels. So whilst 25% of the UK population might be obese, I would suspect that this would be lower if you looked at marathon runners (where one would guess obesity rates would be somewhat lower). So I wondered how cyclists fit in as a group.

A research paper studying the BMIs of people who commute using "active transport" Men and women who commuted to work by active and public modes of transport had significantly lower BMI and percentage body fat than their counterparts who used private transport. (http://www.bmj.com/content/349/bmj.g4887).

From what I can see, 2011 UK data for all adults (men and women)

Underweight (BMI<18.5) 2%
Normal (BMI 18.5 to 24.9) 37%
Overweight (BMI 25 to 29.9) 37%
Obese (BMI over 30) 25%

Ian

[Heltor Chasca]

I'm sceptical about BMI. I'm active. I work physically as a gardener and I cycle. I am short and very muscular. And although I could tone down a bit, this method calculates me as an overweight statistic which according to my last MOT with my GP is incorrect. Bring on the Easter eggs...b

[661-Pete]

You don't need any fancy calculator to work it out, the standard calculator that comes for free on your PC will do the job. All you need to do is work out:

(body mass in Kg) ÷ (height in metres)²

Which is one reason why I prefer to use metric units when weighing and measuring myself.

Bear in mind that BMI is not always a reliable indicator, especially for people over 60 (which includes a lot of folks on this forum). And it should not be used for children.

[Tigerbiten]

The calculator says my BMI's around 27, which is wroung due to my non-standard shape.
I've never worked out how much I have to alter my weight due to my missing arm ........

[Psamathe]

I'm not a health expert but I can see the usefulness of BMI in that it is an easy metric that can provide a general indicator for people. I agree about the limitations but I would imagine pretty well any metric will have limitations and the world can't have an expert assess everybody using MRI/etc. I can see it's convenience for people to measure themselves and thus make things harder for your "couch potato" to fool themselves into thinking they are fine. I would think that most people here (active and more health aware) can interpret their BMI appropriately; knowing if they are under/normal/over/obese.

Also it's convenient for comparison with the general population where data using the same measurement is available.

Ian

[RogerThat]

BMI as a comparative weight index has been widely discredited by numerous health providers around the world, including the British Medical Association and is currently being withdrawn from the NHS as a body index tool. I personally don't think it wise to use it in any statistical way in a Health and Fitness forum.

Your stats from 2011 reveal how out of date the index is and many health professionals consider it even to be a dangerous analysis of body mass. If you've attended hospital in the last year or so you'll notice % body fat is more the standard measuring tool and there are several devices available to measure very accurately body fat percentage, which is a vastly superior (and relatively inexpensive) gauge of your weight and fat proportion.

BMI is (in my estimation at least) a very flawed and impractical tool, especially when applied to active or very active people as it does not have the means to evaluate fat to muscle tissue ratios. It's especially inappropriate in a forum where individuals will have widely varying degrees of fat/muscle tissue composition on account of their activity levels.

I'm wagging my finger at you!

[661-Pete]

In that case, what would you advise as the alternative? Considering that a set of bathroom scales is the nearest thing to a fat-measuring tool that most of us have ready access to.

[RogerThat]

In that case, what would you advise as the alternative? Considering that a set of bathroom scales is the nearest thing to a fat-measuring tool that most of us have ready access to.

I use this at work, and at home for myself. It's £89.99, gives a very accurate body fat analysis and very accurate weight measurement. It's Wifi and Bluetooth enabled, comes with its own android and iPhone app and you can save every single measurement recorded to your laptop, phone or tablet. If you're really serious about your weight control, then for the price of a cheap Brooks saddle it's indispensable. BMI is, in my opinion an anachronistic and perhaps even useless tool in the 21st century. Although the Fitbit will calculate BMI if you read the blurb in the manual it clearly states that % body fat is a vastly superior measurement tool.

Fitbit scale and body fat analysis :


https://baabox.com/fitbit-aria-wifi-sma ... 2wodTiMAJA

[Psamathe]

In that case, what would you advise as the alternative? Considering that a set of bathroom scales is the nearest thing to a fat-measuring tool that most of us have ready access to.

I have a set of such scales (Omron ones so a reputable mainstream make) and the fat %age measurement and muscle %age measurement are useless. They are repeatable in that measure once then repeat and you get very close reading. But measure each day and I get readings between 8.3 to 11.5Kg for fat and 22 to 24Kg for muscle change min to max over a couple of days !!

I can't comment on how imperfect BMI is but I can see it useful to kick somebody into recognising they are not "normal" but actually "obese". Ok, there might be other considerations but you come across a lot of people who deny there is any problem with their weight.

Ian

[RogerThat]

In that case, what would you advise as the alternative? Considering that a set of bathroom scales is the nearest thing to a fat-measuring tool that most of us have ready access to.

I have a set of such scales (Omron ones so a reputable mainstream make) and the fat %age measurement and muscle %age measurement are useless. They are repeatable in that measure once then repeat and you get very close reading. But measure each day and I get readings between 8.3 to 11.5Kg for fat and 22 to 24Kg for muscle change min to max over a couple of days !!

I can't comment on how imperfect BMI is but I can see it useful to kick somebody into recognising they are not "normal" but actually "obese". Ok, there might be other considerations but you come across a lot of people who deny there is any problem with their weight.

Ian

I'm not surprised, Omron are very much at the budget end of measuring devices. The Fitbit scale is currently being evaluated by the BMA as a connected, digital Wifi enabled measure for body fat and mass, to be rolled out in GP surgeries.

I really do not like to see BMI publicized in any form as a tool for body mass measurement as it has been so widely discredeted.
I'm still wagging my finger at you.

[Psamathe]

Your stats from 2011 reveal how out of date the index is ...

The reason the stats I gave were 2011 was they were the 1st ones I came across for the UK that included the %ages for "normal" and "underweight" and I'm not spending lots of time searching for more recent data. sorry but you assumption about 2011 is for my lazyness reasons.

BMI as a comparative weight index has been widely discredited by numerous health providers around the world, including the British Medical Association and is currently being withdrawn from the NHS as a body index tool. I personally don't think it wise to use it in any statistical way in a Health and Fitness forum.

NHS are obviously withdrawing it gven their comment Body mass index (BMI) is a good way to check if you're a healthy weight. (from http://www.nhs.uk/livewell/loseweight/pages/bodymassindex.aspx).

I personally don't think it wise to use it in any statistical way in a Health and Fitness forum.
...
I'm wagging my finger at you! ;)

Sorry. Tough. I don't give a ..... If you can't see this thread for what it is then "get a life".
And if you think enough people are going to participate to make the results "statistical" then we are not participating on the same forum.

Ian

[Psamathe]

In that case, what would you advise as the alternative? Considering that a set of bathroom scales is the nearest thing to a fat-measuring tool that most of us have ready access to.

I have a set of such scales (Omron ones so a reputable mainstream make) and the fat %age measurement and muscle %age measurement are useless. They are repeatable in that measure once then repeat and you get very close reading. But measure each day and I get readings between 8.3 to 11.5Kg for fat and 22 to 24Kg for muscle change min to max over a couple of days !!

I can't comment on how imperfect BMI is but I can see it useful to kick somebody into recognising they are not "normal" but actually "obese". Ok, there might be other considerations but you come across a lot of people who deny there is any problem with their weight.

Ian

I'm not surprised, Omron are very much at the budget end of measuring devices. The Fitbit scale is currently being evaluated by the BMA as a connected, digital Wifi enabled measure for body fat and mass, to be rolled out in GP surgeries.

I really do not like to see BMI publicized in any form as a tool for body mass measurement as it has been so widely discredeted.
I'm still wagging my finger at you.

(I was recommended them by a nurse).

We really can't do anything you like can we. Difficult to please aren't you.

Ian

[RogerThat]

I don't think a BMI survey is at all helpful to anyone actively trying to control their weight.

Perhaps you can explain why you did it, and to what end, and what you hope to achieve by it?

These would be the three criteria I would use, when creating a health survey.

The battle in the modern NHS is as much about education as it is treatment. By pedalling (pardon the pun) outdated and inaccurate ideas and practice, the danger is that people take them to heart. The sad truth is, day after day I'm confronted with patients with wildly erroneous ideas and diet modification plans and it's always the same 'I read it on a forum'. I think the wise among us would agree that it's very important to be selective in the information shared, as people DO read these forums and may well go away taking inaccurate and erroneous ideas with them.

[Psamathe]

I don't think a BMI survey is at all helpful to anyone actively trying to control their weight.

Perhaps you can explain why you did it, and to what end, and what you hope to achieve by it?

These would be the three criteria I would use, when creating a health survey.

It's a little poll out of interest. Nothing to do with "people controlling their weight". Where on earth did you get the idea this was about people trying to control their weight. You seem to be putting 2+2 to get 22 on a number of threads recently.

Sorry. If you disagree with BMI complain to the NHS and get them to remove their advice (I quoted above), complain to the BMA ('cos I note that the GPC are still using BMI in their QOF practices), complain to the people running this forum that your opinion should outweigh the NHS (I quoted their advice before). Write the the government's HSE (Health Survey for England) and get them to stop using BMI (e.g. in their 2015 report), etc., etc. Nobody is claiming it is perfect, but it is something people can do and be sensible about (as I said, a nurse health check calculated mine last summer).

This thread is not recommending or otherwise use of BMI. It is a little survey to see to what extend active cyclists follow national trends. Sorry you are so upset about it. Report the thread. But I'm not going to bother arguing with you any more 'cos it's quite pathetic.

Ian

[Psamathe]

... as people DO read these forums and may well go away taking inaccurate and erroneous ideas with them.

And what advice or ideas is this thread persuading people to take away with them ?

I think the NHS current web page saying "Body mass index (BMI) is a good way to check if you're a healthy weight." (from http://www.nhs.uk/livewell/loseweight/pages/bodymassindex.aspx) makes far stronger suggestions that a little survey/poll on what people's BMI is.

Ian