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The other day I posted an image of a height-weight chart in our members group.
I actually posted it to see if anyone else picked out what my wife and I did (great minds think alike / fools never differ).
Badly phrased, it said you were overweight “if you weigh more than 10% of your ideal body weight”.
Ie: If my ideal body weight is 190lbs, I’m overweight if I weigh more than 19lbs. Not if I’m 19lbs over the 190. Just if I’m over 19lbs. Which I haven’t been since I was one year old.
But most people’s comments, understandably, were with regards to the weights suggested on there.
Many thinking that they were unrealistic or unhealthy targets.
And some asking for my opinion on them and things like BMI.
So, I’m kinda going to share it here.
Not actually my opinion though.
I’m going to share what the data says.
And a little of what I’ve found from my own experience.
What You Need to Know About BMI
In an industry where many of our contemporaries just peddle the version of things that they like the best………..
We try and be as evidence-based as possible.
In my opinion, many within our industry show almighty levels of arrogance to not only disagree with what thousands of experts have found over millions of hours of study……….
But to often not even read up on the above before dismissing it in favour of what they “feel is right”.
And, to be honest, we’ve been guilty of this on occasion.
Just, hopefully, fewer occasions than most.
Results of Research on BMI
So, what does the data show?
Stripping aside opinion and emotion, what do the majority of the peer-reviewed studies suggest?
Well, it shows that for the majority of the population, BMI is reasonably accurate in showing someone’s “ideal” weight range (I’ll come to what “ideal” means in a mo).
It doesn’t work as well when you’re particularly tall or short.
Or if you have particularly high or low muscle mass.
The 5% or so ‘outliers’ at either end.
But for the 90% or so in the middle?
It’s not going to be too far off the mark.
Same with height-weight charts if they give a range rather than a specific number.
Fine for all heights as it, obviously, takes that into account.
Doesn’t take into account muscle mass, so not great for those outliers again – but the majority of the population aren’t too dissimilar on this front.
You’ll notice I said reasonably accurate.
Not mega precise.
To be used as, at best, a rough guide.
But, from my experience, if a chart (from a reputable source) suggests someone is 3 stone from their ideal weight……….
They could definitely lose 2 1/2 stone and not be underweight.
No emotion here.
Not saying you should be or have to be any particular weight – it’s your life and body, do with it as you wish.
Just saying that the body of evidence shows that most height-weight charts and BMI won’t be too far off the mark on “ideal” weight for most people.
From our experience, most people (ourselves included) underestimate how much weight they could (not should) lose.
BMI Vs. Height-Weight Charts
When I left Uni I was 16st 10lbs.
According to BMI, for my height I should be between 10st 6lbs and 14st 2lbs.
Most height weight charts suggest 13 to 14 stone.
I thought those numbers were madness.
I was a “big lad” and couldn’t see how I could drop that much weight.
When I left Uni and decided to get in shape, I quickly dropped to 13 stone.
Having gained muscle since then, I now hover just under 14 stone when my body fat is at a level I like.
A little over 14 stone when it creeps up.
For most people, unless they’ve been quite lean, they underestimate the weight loss that would get them to that point.
Again, I want to make clear that we’re not saying anyone has to get to those weights.
Or making any judgement on or putting any emotion to anyone’s weight.
Not the way we roll.
And we’re not saying anyone should even want to get to those weights – many find a level at which they’re happy with the balance of the life they are living and the weight (and, more importantly, everything that comes with that) that takes them to.
Your “ideal” is your ideal – you chose what you think is appropriate.
Just saying that the body of evidence suggests that BMI and height weight charts are reasonably accurate for the majority of the population in showing the weight they would be if they weren’t carrying extra weight above what is ‘necessary’.
Jon ‘BMF’ Hall and Matt ‘BLT’ Nicholson
P.S. If you like the idea of an approach that is evidence (rather than opinion) based and non-judgemental, check details of our briefing meetings in Macclesfield for the next step.
RISE Macclesfield – myrise.co.uk
Serious transformations. Fun times!
Enter your details at myrise.co.uk for more information about what we do.
Or check out our monthly find-out-more meeting if you want to learn more about our free ’20lbs weight loss in 8 weeks’ and ‘Beach Body’ challenges –>myrise.co.uk/briefing-meeting