To wonder why people pay so much attention to BMI, when waist to height ratio is a better indicator?

[WaisttoheightnotBMI]

Many scientists have said for years now that BMI is outdated - it shows how much you weigh but not where you carry most of that weight.

This is really important for women, because many women are pear-shaped. Carrying fat around your lower half means you're carrying a lot of subcutaneous fat, which can actually protect
your health from serious illnesses like heart disease compared to carrying a lot of visceral fat (around your stomach, which is dangerous as its near to your internal organs).

So you could have a higher BMI but a healthy waist to height ratio because your waist is small or average in proportion to your height.

Take this from Harvard www.hsph.harvard.edu/obesity-prevention-source/obesity-definition/abdominal-obesity/:
"The study found that even women at a “normal weight” BMI less than 25 were at a higher risk, if they were carrying more of that weight around their waist".

Also from Harvard www.health.harvard.edu/staying-healthy/big-thighs-may-be-wise#:~:text=Researchers%20tracked%20the%20volunteers%20for,than%20those%20with%20thin%20thighs.

"Although the BMI provides a reasonably accurate reflection of body fat, it does not tell how that fat is distributed. Research shows that not all fat is created equal. In fact, fat plastered around the body's internal organs (visceral fat) is much more dangerous than fat layered beneath the skin (subcutaneous fat); that's why liposuction and "tummy tuck" operations may improve your profile but won't help your metabolism or your health".

I feel like people here frequently talk about BMI and judge how healthy someone is or isn't based on their BMI, when that's not even the most effective indicator - could we start considering waist to height ratio more now?

I still think it depends on your body shape - since it’s not possible to spot-reduce fat, I’m not sure what else a person could do if they are already a healthy weight but their waist is “too big”

"The study found that even women at a “normal weight” BMI less than 25 were at a higher risk, if they were carrying more of that weight around their waist".

I’m 5’7 and weigh 10.5st and a body fat percentage of 23% so well within a healthy range, but I have a tiny bum and legs, but broad shoulders, massive 34H boobs and a round tummy - there is just nothing I can do about that, it’s the way I’m built. I think it’s a shame that because of one measurement I’m deemed unhealthy 🤷‍♀️

@Iamclearlyamug

I still think it depends on your body shape - since it’s not possible to spot-reduce fat, I’m not sure what else a person could do if they are already a healthy weight but their waist is “too big”

"The study found that even women at a “normal weight” BMI less than 25 were at a higher risk, if they were carrying more of that weight around their waist".

I’m 5’7 and weigh 10.5st and a body fat percentage of 23% so well within a healthy range, but I have a tiny bum and legs, but broad shoulders, massive 34H boobs and a round tummy - there is just nothing I can do about that, it’s the way I’m built. I think it’s a shame that because of one measurement I’m deemed unhealthy 🤷‍♀️

Thank you for your response - I totally see what you mean and you're right we can't spot-reduce fat. I think my issue is so many people here rely on BMI like its the be-all and end-all - they'll say your BMI is 25, you're overweight and need to lose weight, or your BMI is 19 so you're healthy. When in reality they know nothing about that person's body shape/fat distribution and so they may actually be in a much better position than BMI lets on. I just think it's important to be aware of that, and that waist to height ratio is often more informative than BMI about health and risk factors.

Outdated is the wrong word, BMI is limited not "outdated"

MNers are obsessed with BMI.

I agree that waist measurement is an important guide to whether you're at a healthy weight.

I have however noticed that people who say on MN that BMI is bollocks because they're a size ten at BMI 32 and they look "gaunt" if they drop below a BMI of 28 (I may be exaggerating for effect) normally go very quiet if you say "possibly, we're all different, what's your waist measurement?"

@lljkk

Outdated is the wrong word, BMI is limited not "outdated"

MNers are obsessed with BMI.

Exactly. It tells part of the story. Waist/height ratio tells another.

Unfortunately, like most things in life, health is a little more complicated than a simple measurement. But they are all tools to prompt thought about whether you need to do something. That is their power, along with their simplicity

It's so weird as really nothing tells a complete story

I was 5 stone overweight (obese) with a 29 inch waist - I'm an hourglass shape (my BMI was 38)

Now I'm 1 stone overweight, not obese and my waist is 25 inches (BMI 28)

BMI is a joke, think about Rugby players or strongman competitors they can be mega fit but their BMI is morbidly obese. The healthy BMI limit doesn't make sense, for me to be a healthy BMI I would have to weigh under 9 stone but when I lost weight & got down to just under 10 stone I looked like I was dying, I didn't have an ounce of fat on me.

Being morbidly obese doesn't stop Sumo wrestlers from being very fit.

that fact Doesn't make it perfectly healthy for office admin occupation Jo in Swinton to have a BMI of 35.

Doesn't really matter what the measurement is, you will still get people denying they're overweight. If it's not "oh, but rugby players" it'd be "oh, but I just carry more weight there." Either way, people will carry on insisting they look "gaunt" at below 10st or a size 12.

Yes, BMI isn't perfect, but on a population level, it's one of the many tools you can use. Funny how people saying "oh but what about pro athletes" are never pro athletes. And in fact most very muscular sportspeople would be well within a healthy BMI range anyway.

I am similar to @Iamclearlyamug.

I am apple shaped and as I'm short and also short waisted it's the worst combination. My waist measurement will look large whatever my weight and I have big boobs and broad shoulders too meaning my BMI will rarely be much under 25 but my waist will measure much larger than average no matter what I weigh. My healthiest weight is between 9 and 9.5 stones although I'm normally heavier. Even at 8 stone my waist was over 30".

BMI is terrible, as it assumes people are flat, and that everyone has the same muscle percentage, so short and muscly people appear fatter and tall and weak people appear thinner.

However you can calculate BMI easily and quickly and is a good ready reckoner for ‘Miss Average’.

In RL the only person Ive met who disparages BMI is morbidly overweight. Yet seems to use "look at rugby players" as an excuse to dismiss their massive BMI.

Its not a fail safe tool but it is a good indicator (amongst others). And is a lot easier than measuring waist size

Whilst they aren't a total fail safe I have some "smart' scales that measure loads of different components and indicate which bit is in a healthy or unhealthy range

Everything on mine is green except bmi and weight. Body fat coming in at 24% too (green). Visceral fat is on the higher side but still in a green zone.

No I know these scales aren't 100% accurate but nothing the average person can own will be and it's the best I can do.

My other niggle with bmi calculators is the activity amount - even the nhs one the most activity you can put in is 150 mins a week. I gym/home workout with cardio and weights 6 days a week and average 350 to 400 active mins a week - telling me to "exercise more" really isn't the issue. And calorie wise I aim for 1200 to 1500 a day (pretty healthy balanced diet bar the odd biscuit and pint) so unless I'm going to totally stop eating I'm at a loss to how to get bmi down further.

BMI is a range precisely to accommodate a range of body types and builds! The weight range for a given height to be within the healthy range is very large.

I think there are vanishingly few athletes who fall outside of a healthy BMI. And I wouldn’t consider strongmen or Sumo wrestlers to be healthy - carrying that much extra weight has serious effects on joints and circulation.

I have gained some weight, I weighed myself recently and I just tipped the obese number of BMI. I'm very curvy but I certainly don't look obese. I have big hips, bum and boobs and strong muscly legs and a flat stomach and a petite face. However I am now on a diet to lose a few lbs as was feeling the strain on my joints a little and was starting to get a double chin.

@Cheesechips

I have gained some weight, I weighed myself recently and I just tipped the obese number of BMI. I'm very curvy but I certainly don't look obese. I have big hips, bum and boobs and strong muscly legs and a flat stomach and a petite face. However I am now on a diet to lose a few lbs as was feeling the strain on my joints a little and was starting to get a double chin.

But obesity is so common now, most people who are don't look it. Particularly st the lower end. Our expectations have shifted. Strain on joints and double chin are definitely signs of obesity.

I would be the same as you btw, my stomach never really puts on weight. It's all bum, boobs and face. So I could argue that the waist height ratio doesn't work. But it's like bmi, in that is shows part of the picture.

Good for you for not burying your head in rhe sand until it becomes even more difficult to loose. And good luck for your weight loss

Arbeity thank you! I was always surprised when reports say how many people are obese but then when I tipped that mark I saw why. If I tell people my BMI is obese they give me a look I just don't want to set myself up for problems as I get closer to 40. Running for example hurts my ankles and knees a bit even though Im fairly fit. Low carb is helping!

Practicality I think - BMI is very simple and doesn't change much depending on who's measuring. If you've got to measure someone's waist that's an extra faff, and also you've got to judge exactly where their waist is. Almost anyone who's had a baby will be able to tell you that their fundal height seemed to be measured differently each time - I imagine waist measurement would also suffer from this.

BMI is only one part of the picture - there's also bodyfat ratios you could look at as well as waist measurement, given that BMI is also affected by having a lot of muscle. To say nothing of lifestyle - a smoker with a BMI of 23 is quite likely to be less healthy overall than a non-smoker with a BMI of, say, 29, even though the non-smoker is overweight. But it's a very easy part to measure and standardise, so I can see why it's used so much.

You can lower your BMI by losing weight, but you can't change how your body distributes fat, so it makes more sense to focus on BMI as it will be meaningful to everyone.

My doc told me about waist/height measurement years ago. I've seen the conversation on here with regards to waist measurement which also doesn't make sense (eg to ignore height).

It's so weird as really nothing tells a complete story

I agree, build & shape can make such a difference.

I don't think either way is perfect as a blunt tool. I'm very slim, have a BMI of 18.5 but due to my body shape am very straight up and down and have no waist and narrow hips. I have barely any fat on either my belly or hips but my waist hip ratio is 0.83 due to my natural frame, which is only just in the "healthy" category.

I also think BMI works well for average heights but not so weep for short or tall people.

Its just a rough guide. If your BMI is over 30 you probably need to lose weight. If you a professional sports person you probably have access to a trainer who can give you tailored advice.

I know from experience the healthy weight for my body is about 10.5-11st, at the upper end of of the healthy BMI range. It appears im dense. I'm currently a lot above that and trying to lose weightvand get some fitness back.
My daughter is still young, but her Child BMI is on the 8th Centile.... but she's definitely healthy. She just has long legs and a narrow frame.

BMI isn't perfect but is a good general indicator. Personally not something that keeps me awake at night!