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Many scientists have said for years now that BMI is outdated - it shows how much you weigh but not where you carry most of that weight.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

BMI isn’t perfect but it does work for the majority. The healthy ranges are huge so different body types are accommodated. The “rugby player” excuse so many trot out in these threads doesn’t apply to the majority of the population. If your BMI shows you are overweight or obese you probably are.

I think waist to height ratio is much easier to measure than BMI, you just need a piece of string, you don't even need to know your weight.
And for people saying 'oh that doesn't work for me because I'm an apple shape' isn't that the point? Fat around your waist is more risky than fat elsewhere? So sorry, but it's worth doing something about.

And for people saying 'oh that doesn't work for me because I'm an apple shape' isn't that the point? Fat around your waist is more risky than fat elsewhere? So sorry, but it's worth doing something about.

If you have narrow hips, it's hard to achieve the supposedly healthiest ratio, even if there's very little fat round your middle.

I find the "professional rugby player" excuse is usually best countered with "are you a professional rugby player." And the answer is invariably no.

The answer is usually closer to "well no, but I chuck a kettlebell around a couple of times a week so like to pretend I'm muscular, when in reality I'm just in denial about my weight."

That was me, for years. Then I finally gave up making excuses and lost the weight. Turns out I wouldn't look "gaunt" at a healthy BMI after all. Who knew?!

There's a hip/waist ratio, too. Bizarrely I fell foul of that one when I lost weight. Mine got worse rather than better.

No one ever talks about fitness, but surely that's more telling than BMI?

Why don't we have standardised norms for physical activity, like a staircase test and a standing with your arms out test?

My BMI was bad for years. It's much better now, but what makes a difference day to day is how fit I am. I've been obese and fit, and obese and unfit.

Fitness is a better indicator of health than appearance, weight or diameter surely?

A nutritionist reassured me that BMI is a number, not a fitness indicator. It points you in the direction of potential issues. What matters is cholesterol level, blood pressure, blood sugar levels etc. If all those indicators are good, BMI doesn't matter.

I also had a nurse look like she was sucking lemons because my middle age road test result came out green despite my obesity. Not smoking, drinking, being active, low blood pressure and cholesterol all outweighed my obesity. She'd been expecting a glaring red klaxon and seemed most disappointed I wasn't likely to die in the next ten years.

Bizarrely I fell foul of that one when I lost weight. Mine got worse rather than better.

Yes, I am similar. My hips seem the go-to spot for my body to take fat from, for some reason. I end up with concave buttocks if my BMI gets below 20, but my waist never gets particularly small.

BMI is straightforward and gives people a goal to aim at.
I need to lose weight and it’s easier to set a goal of losing 2 stone than losing 3 inches off my waist.

If someone is obese or top end of overweight then they are likely to need to lose weight whatever measure you use.

I urge you all to be 65+:o

My rheumatologist said I needed to lose some weight and build up my quads to take pressure off my sore knees: some osteoarthritis, but general wear and tear, and not why I am referred to him.

I go by clothes fit so knew I was overweight. Did the BMI = overweight. Did the 65+ BMI =normal. Unkindly the scale is called geriatric, but there you go.

Anyway, I'm on it, have painlessly lost several kilos, got the legs going, etc.

I’m an hourglass so I gain weight pretty evenly everywhere. The only part of me that really stays slim is my back and shoulder region, everywhere else gains. I don’t know where my body shape falls in this thinking since I gain a big bum and also a bit around the mid section. I prefer to go on BMI, easier to manage my weight relying on that.

@fellrunner85

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.

This, 100% 👏👏

If you're overweight then you're overweight and all the arguing over BMI and everything else isn't going to change that.

BMI is still one of the most useful measures we have.

25 or 26 or 7 isn’t going to make a huge difference. Over 30 is definite increased risk. BMI over 40 and the risk is high and on average leads to a reduction in life expectancy of about 10 years. Also longer spent living with a long term condition or disability.

A lot of rugby players do have excess fat not just muscle… doesn’t mean they’re healthy either.
www.shs-conferences.org/articles/shsconf/pdf/2019/09/shsconf_shw2019_02011.pdf

Yes definitely better to be fit than not (ie doing physical activity) but longer term there isn’t evidence that it just cancels out the risk from obesity. Just as it doesn’t for smoking. Risk is multi factorial and we have to look at our lifestyles holistically.

BMI is a blunt tool but a useful one. It can be useful in conjunction with other measurements, such as hip/waist and height/waist ratios.

It doesn’t necessarily correlate to health but can be a useful way of identifying other issues. Generally speaking if you have a BMI of 30 you’re going to be rather overweight and conversations about diet, exercise, family risk factors, lifestyle risk factors etc are important.

BMI in isolation doesn’t tell us much and is certainly less helpful if you can’t see the person.

The two are not contradictory. If you have a BMI above 25 then chances are you’re carrying so much excess fat that it’s impacting your health. For some people, carrying excess fat starts to affect their health at BMI slightly below 25. For these people, a BMI of 23-25 isn’t healthy - they need to carry even less fat overall to compensate for the fact their body lays it down in the worst place possible.

The healthy range for BMI can be huge, especially for taller people. A BMI of 24 isn’t the sign of good health that some people take it to mean - it means that you’re potentially carrying 2+ stone of extra fat that you don’t need, but it’s probably not yet harming you. However, if that fat is mostly around your middle, then that fat could kill you.

Alternatively, they could just bring the healthy BMI limit down to 23, and treat everyone like they might be apple shaped. Weight lifters and professional rugby players aside, I doubt there are many people who wouldn’t benefit from losing that extra stone.

And for people saying 'oh that doesn't work for me because I'm an apple shape' isn't that the point? Fat around your waist is more risky than fat elsewhere? So sorry, but it's worth doing something about.

@Ihaventgottimeforthis but HOW do you suggest this is done when you cannot spot reduce fat? As I explained upthread, I am already a healthy weight, with a very good body fat percentage - but my hips are a full 4 inches narrower than my waist, my bottom half is tiny (I can fit size 8 low rise jeans) but with 34H boobs and wide shoulders I carry more weight up top. If I lose more weight my legs and bum will get even smaller, but my boobs and stomach stay the same whether I’m this weight or 2 stone heavier .

I’d just be interested to know how I can lose weight JUST from my stomach, because if you know the answer you will literally be a millionaire and scientists will bow down to your knowledge 🤷‍♀️

BMI is also ethnicity dependent. The NHS, and the Indian health authorities advises that people of South Asian descent should aim for a BMI below 23. China and Japan set a cut off of 24. Those three countries also set their obesity cut-offs lower.

yabu

both bmi and waist measurment together give a good prediction of health.

if anything, as pp say, the top end of 'healthy' bmi range is too high for many ethnicities.

I think if you are an apple shape the unfotunate truth is that you have a lot less leeway on how much fat you can healthily carry than a pear shape can. Unfair but that's life.

@iloveeverykindofcat

I think if you are an apple shape the unfotunate truth is that you have a lot less leeway on how much fat you can healthily carry than a pear shape can. Unfair but that's life.

Like a pp said, you have to look at it holistically. Someone with a ginormous bum and tiny waist might still have furred up arteries, and if they're overweight they'll be putting strain on their joints and so on. I accept that, all things being equal, an overweight pear might be less at risk than an overweight apple, but how often are all things equal?

Id never heard of waist to height or hip to waist ratios. Tested it out and I'm healthy on both. My BMI is 23 and I am a natural pear shape. 5'8 as well. I don't look good under 10 stone. 10st 7 is perfect for me but I'm above that at the moment!

Possibly in part because stepping on a scale is easier & more socially accepted than getting out the measuring tape, which can seem to some to be overkill and there are arguments on where exactly people should be measuring against our different proportions.

BMI is a joke, think about Rugby players or strongman competitors they can be mega fit but their BMI is morbidly obese

Being strong doesn't mean being fit. There are people who can lift or push a fuckton but are in poor health.

There is argument in the "overweight" category and around where the cut off should be because there is evidence, particularly as we age, that there is protective benefits of being a bit heavier. Our rigid categories there have a lot of limits before getting into ethnicity, sex, disabilities, social attitudes and more. It's why it's better to have more types of data and a wider discussion on benefits and risks & how they vary for different groups and for individuals.

Once we hit morbidly obese (over 35 BMI), then that argument falls apart and really, a lot of muscle also raises the risks of certain health issues. It's very taxing on the body and those athletes are at high risk for many health issues from joint problems to recent research that strongly suggests that intense sports - including rugby - may increase the risk of MND and other conditions.

Whether those risks are worth it is up to the players, but we shouldn't be using people at the extremes as examples just because they can do things many people can't as if that strength is all good or their situations can be applied to others who are the same weight.

@Ihaventgottimeforthis

I think waist to height ratio is much easier to measure than BMI, you just need a piece of string, you don't even need to know your weight. And for people saying 'oh that doesn't work for me because I'm an apple shape' isn't that the point? Fat around your waist is more risky than fat elsewhere? So sorry, but it's worth doing something about.

Yes I agree with you that’s exactly the point! Apple and pear shapes could have the exact same BMI but the apple shape is at more risk so they shouldn’t be complacent about it. In that case if their waist is disproportionately big, they can try to lose weight - yes it’ll take longer to lose weight from their waist because those women lose weight around their legs and hips first, but eventually the weight loss reaches the stomach (and the reverse is true for pear shapes). I think this works for a lot of people, but I acknowledge it’s trickiest when you’re very very Apple shaped - because you really wouldn’t have much to lose at the lower half so can’t really try to lose more.

@ClariceQuiff

And for people saying 'oh that doesn't work for me because I'm an apple shape' isn't that the point? Fat around your waist is more risky than fat elsewhere? So sorry, but it's worth doing something about.

If you have narrow hips, it's hard to achieve the supposedly healthiest ratio, even if there's very little fat round your middle.

That’s not really true though because we’re talking about waist to height ratio, not waist to hip ratio. If there’s very little fat around your middle you’ll have a small waist so when measured against your height, you’ll have a good waist to height ratio regardless of how narrow your hips are. That’s the case for a lot of celebrities - many have straight up and down bodies, so their hips are narrow but their waist is obviously small too.

@LaurieFairyCake

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)

Yes this is the kind of thing I'm talking about - unless you're very short, a 25 inch waist is small and you probably have a good waist to height ratio and are healthy in that aspect, which you can't tell from BMI.

@ColleysMill

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.

That's interesting, what smart scales do you use if you don't mind my asking?

@DazzlePaintedBattlePants

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.

"BMI is a range precisely to accommodate a range of body types and builds!"

I don't think that's how people, especially on MN, see BMI though. They'll see someone with a BMI of, say 24.5, and say well you can lose 15kg/ 2.5 stone and still be a healthy weight so you should work on losing weight - when in reality, because of the distribution of fat they may already be very healthy, and losing another 15kg may not be of much help to them, not to mention very very hard to achieve.