To think it’s time to scrap the concept of BMI?

[AnyoneWhoHasAHeart]

There’s a lot of talk these days about the obesity crisis, and what a healthy weight should be. And I totally agree that we absolutely are in a place where obesity is definitely a thing.

However, there seems to be very little talk about what is at the other end of the scale, and being. Underweight seems to be a trend people want to aspire to.

I calculated my BMI this morning, and it told me I have a BMI of 21.

I’ve just spent four months in hospital, have had major surgery, and lost an astronomical amount of weight. I wasn’t overweight to begin with, but I am 5ft 2, and I currently weigh 44kg. I don’t need to be told I need to gain some weight at least, and I am trying, but I’ve lost my appetite so that’s a process.

But calculating my BMI this morning it said that my BMI is 21, which is almost at the upper end of the scale, however it then goes on to say that a healthy weight for my stats is between 47/60kg. So how exactly does that follow?

If you’re looking at BMI only you could be forgiven for thinking that 44kg is a healthy weight, when trust me it really isn’t at this point.

So how many people are being told they’re obese based on these types of calculations where actually, they’re probably not?

We Need to start looking at weight not BMI, because it’s just not accurate.

Someone with an hourglass shape has a small waist surely? That's the point of the shape name. Apples and rectangles have a wider waist.

Please link to the tool you used, as it is clearly faulty.

It does in that it is so wide. As pp pointed out, she could be between 7.5 stone and 10 and still be regarded healthy. I am 23 bmi and am very muscular. The scale is so wide that me with my big muscles am still seen as normal. Anyone with a bmi over 25 and thinks they are ok are kidding themselves.

It’s rare to see an OP who is so absolutely right and so absolutely wrong at the same time.

BMI is a ridiculous tool. Some people can be a very unhealthy weight in the healthy range. When it says 18.5-25 is “healthy”, it doesn’t mean “as long as you are in there, you’re a healthy weight” it means “your healthy weight could be anywhere in here”. So, someone with a BMI of 18.5 could be dangerously underweight for their body, someone with a BMI of 25 could be overweight for their body. Bodies are built differently and small-framed, narrow-built person would really feel unwell at a BMI of 25, and people who are higher-metabolism or wider set may find themselves losing hair, stopping periods or fainting if they go below 20.

It also ignores that there’s a healthy balance of fat and muscle - a very low body fat is very unhealthy, even if you make up that mass in muscle. So, a woman with a 12% body fat but high muscle mass isn’t healthy and her BMI would be. At that BFP, you’d likely see all kinds of issues including seizures, migraines, etc - but would be a healthy BMI.

This wouldn’t be such an issue if our medical system weren’t so reliant on it. If a woman with a 12% body fat and BMI of 20 went to a GP complaining of migraines - the BMI is healthy so her unhealthy body fat would be ignored.

And all of the above is the problem for the (roughly) 50% of people that BMI is actually applicable to in the first place!

Height to waist ratio, whilst not perfect, is more accurate and simpler. In light of that, BMI serves no purpose.

Ilona Mayer and Christine Ohuruogu aren’t just “kidding themselves”, they managed to kid entire Olympic committees and teams of Olympic doctors…

Honestly, people thinking that they’re sooooo muscular or fat with a BMI of 23 or that they’re soooo skinny with a BMI of 21 that there’s no way anyone could be bigger/smaller and healthy (against all known and proven medical fact) are so strange. All you’re saying is that you have body issues.

Yeah exactly. I've always had wider hips and a narrow waist. And yet my waist was still too wide compared to height. Not challenging it, just amazed me!

Have you used NHS calculator? Can you post your link?

It really is brutal! Mine comes out a bit above 0.5 … ah, I’m sure that’s got to be the muscle thanks to my Pilates instructor.

Possibly the OP wrongly used the child version of the BMI calculator? That can make a difference.

1. OP miscalculated her BMI
2. OP misinterpreted the result she did get
3. OP is at the end of four months in hospital following major surgery at which point, BMI is not really a relevant tool.

Based on this she thinks it should be scrapped? No.

I see what you mean. After your post I measured mine and I am within healthy range with a BMI of 19 but there isn't a whole lot of wiggle room. If I put on weight I could still have a healthy BMI with an increased risk height to waist ratio. I'm a rectangle.

I think BMI is fine. Most of us are not muscly rugby players and therefore it is pretty accurate and helpful.

I think it's a reasonable guidance. And shouldn't be scrapped

@Thistletwo I have a BMI of 26 and I genuinely think i am OK. I'm doing a half ironman next month. I did a half marathon last month. I have a very active lifestyle. I'm just a female endomorph, which larger than average breasts and muscular legs.

BMI works for the vast majority of people (there are some that it doesn’t, eg professional athletes with a lot of muscle, but that’s not most people).

You normally find the people criticising it don’t like the results (e.g, it’s telling them - correctly - they are fat).

Mixed feelings about this one . I spend all my teen years thinking I was fat as a size 10 , I’m now a size 16 and while I accept expectations change and girls like to be curvier , I still look at some supposed fit girls and think “ she is bound to be overweight “ and I bet they have a high fat percentage .
Im not saying people are not pretty or perfect as they wish but there is a difference between stereotypes and healthy . I think BMI still is accurate when it comes to health risk .

I must admit that while the waist to height measurement may be useful, again I rather suspect it is too blunt a tool and may not sufficiently take into account different builds, and also age.

You need to convert your height into cm rather than feet & inches.

Looks like BMI is pretty accurate for you.

Perhaps we need to focus more on maths skills in schools. It's very simple arithmetic!

🤣 It benefits me because I’m 5”8 with a small waist and wide hips (most of my fat is carried on my arms, hips and legs) so with both ratios even at an “overweight” BMI, I was fine. It’s only if my BMI crept up towards the obese category that my waist got too broad.

It’s funny, I used to see loads of women with my shape (I think they even used to call it the “typical British pear shape”) but now I do seem to see many more women with a thicker trunk/bigger stomach, yet relatively slender limbs. I know it’s not good health wise but a part of me envies that it’s easier to dress that body shape- I never wore sleeveless things or short skirts/shorts etc even when young 😢

BMI is a blunt but useful instrument. People of same height and weight can look different and body composition can be quite different.
No one should rely on one measurement. And weight also isn’t an indication of health. Either end of the ‘scale’ is not good but there’s quite a broad range in the middle. My DS gf looks totally fit if a tad on the thin end but she can barely lift a tin of beans. His previous gf was about two stone heavier but had amazing endurance, though was probably in the ‘overweight’ category of BMI. But she was much healthier.
In all cases it’s as @BangersAndGnashsays, common sense should prevail.

It's not just about weight, but weight distribution as well. My GP said waist circumference is a better guide than BMI.
In which case I have my work cut out!

It’s a population based tool with limits at an individual level but at the moment we don’t have anything better.

It should be interpreted sensibly in the context of individual factors like height (much shorter or taller) body composition and types (such as muscle).

Sorry you haven’t been well. Hopefully as you start to eat regular small meals your appetite will slowly increase to manage bigger portions, that’s what happened to me.