Measuring weight: the body mass index (BMI)

Weight and size matter because they can affect a person’s health and wellbeing now and later in life. Most children are weighed at school so that doctors can help them and their parents ensure that they are a healthy weight. Here we will talk about what young people and their parents said about the Body Mass Index or BMI which is a measure used by doctors for deciding if someone is a healthy weight.

What is BMI?

The body mass index is a calculation of body fat that takes into account your age, weight and height. The result is given as a number. For adults the BMI categories are:

  • Under 18.5: Underweight
  • 18.5-25: Normal weight
  • 25-30: Overweight
  • 30-35: Obese
  • 35 and over: Morbidly Obese
In children and teenagers (below the age of 18), weight is compared with other people of their age, height and gender. BMI is then given as a percentage or ‘centile’ of this group.

Some people think that Body Mass Index (BMI) is not a good way of deciding if a person is overweight or obese. It is especially difficult to say if a child or young person is overweight or obese because they are still growing and each child grows at a different rate. Most of the young people we talked to accepted the BMI as a measure, as long as it was only used in a medical sense (by doctors or other health professionals). Many felt unhappy about the words used with the BMI and didn’t like to think of themselves as being ‘obese’.

The Body Mass Index explained

Among the people we spoke to, there was a lot of confusion about how BMI is measured in adults and children. A few people said they think that BMI is not a good way of measuring whether a person is overweight. Some young people understood it and said they accepted they were ‘obese’ but others rejected their BMI measurement.

Huw explains why he doesnt accept that the BMI is relevant for him.

Gender Male

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Okay, well for one, I think the BMI is a stupid, because I think it’s so unrealistic because if you want to be a healthy weight, surely a BMI’s is what aim for, but it’s a bit unrealistic. I mean ideally I would want to be about 18, 17 or 18 stone, which is probably a bit optimistic, but it’s a lot better because my BMI said I should be about 15 I should think, which is a bit, which is way too optimistic. I mean I couldn’t get down to 15, most of my friends weigh more than 15, and they’re stick figures, so I think the BMI is just stupid to be honest. It doesn’t take into account anything. I think so, that’s what I’ve qualify as a healthy weight, and it’s more just…

Sorry, which one do you qualify as being a healthy weight?

The one, the one I’m aiming for, the…

Okay, so that’s 17, 18.

17, 18, rather than the 15, 16. So I think it’s more like toning up because you see body builders who are very, that’s why it’s overweight because it’s muscle, so I want to get rid of the fat and change it to muscle which is why I’m doing a bit of weights in the gym because, of the cardio, of the cardiovascular burns the calories, it’s no good if you’ve, it’s harder and sometimes you just want to tone up the fat your body’s got, which is quite nice.

Can you tell me what BMI is, and what your understanding of that is?

Okay, the BMI is the Body Mass Index, which is a way of determining how heavy you should be according to your height, but it doesn’t distinguish between men and women which is one of the problems, and so I find it a bit general I think. You can’t have one for everybody – everybody’s different.

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Sara thinks the BMI is a ‘flawed’ way of measuring if someone is a healthy weight.

Age at interview 47

Gender Female

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It’s very difficult when I think one thing that I notice is that you’ve got statistics. You’ve got things. One of the worst is this BMI, this body mass index which is so flawed and yet they still rigidly stick to it. And when I just recently took up, changed life insurance I was quizzed at great length because my BMI was too low. But I mean if anyone looked how fit I am and strong I am and, you know, it’s not a problem. And then, you know, we have these famous instances of athletes and things whose BMI is off the scale. Officially they’re obese but they’re not, there’s not an ounce of fat on them. They’re just rock solid muscle and heavy bone from all the exercise they do. And I think with, within the healthcare there is this sort of, oh height this, weight this, oh well that sounds alright, that’s alright. But that’s, that’s not it. And people, there’s a huge variety of things that are perfectly healthy and right and there are also plenty of people who are, the numbers will say that’s ok but if you actually look at them it might not be. I mean my daughter, I don’t think my daughter’s weight is very high but you look at her and you can see it’s not in proportion and there’s too much fat and not enough muscle. And it’s got to change for her future health.

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Some parents we talked to admitted they knew very little about the BMI, or about how their children’s weight was categorised.

Charles has heard people talking about his son’s BMI but no one has really explained it to them.

Age at interview 44

Gender Male

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The BMI index, the only time the first time I heard of the BMI index was when my son went to the gym and the gym instructor started talking to him about it. And set, tried to set him targets about using your BMI with certain number but it meant very little to me. No one’s really explained what it is or

Does it mean something to your son?

I’m sure it probably does because he knows what it is. And the, the computerised generation that they live in the gym has all these systems in place and it it’s all technologically, technologically interesting for them to, to have all these things that they can challenge them.

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Feelings about the Body Mass Index

Lots of people, including parents, really disliked the terms ‘obese’ and ‘morbidly obese’. They said obese was a ‘horrible’ word and that once you were given that label it was difficult to shake it off. Obese had unpleasant associations with words such as ‘grease’ and ‘fat’; to one mother it also suggested that the person was ‘fat and thick’.

Anaan accepts she has ‘weight issues’ but won’t accept the labels ‘obese’ and ‘overweight.

Age at interview 18

Gender Female

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Anaan’ It’s simple really. I don’t look in the mirror and think you’re obese, you’re overweight. I just find those two words really negative, and the connotations that they have are just horrible. You know, I mean ‘obese’ – it always makes me just think ugh kind of thing, it really does, the word ‘obesity’ is just such a horrible disgusting word for me that it’s not something I ever want to attach to my name. I’m not ‘obese’ as far as I’m concerned; ‘overweight’ not even. Yes, I have weight issues, but I wouldn’t say I was overweight. I might be but that is not something I would use to describe myself. It’s not something that I even look at when thinking of myself, as a person whos a bit bigger.

Yes, I have weight issues but I’m not ‘obese’ and not ‘overweight’, and I would hate for other people to describe me using those two words, or attach [to] me, to anything and use those two words, because I’m not. That’s just the way I feel. I am not obese and I am not overweight and I really hate those two words. Because I think whenever you say that someone is that, it instantly makes them feel worse, because no one likes to be called overweight, and no one likes to be called obese. So, I don’t use it to describe other people and I wouldn’t want anyone to describe me using those words. And yes they are more matter of fact or whatever, but they’re just not nice, and you know, by telling people that they are these things, you’re not helping them I don’t think really you are going to come to terms with their weight problems, because they just ugh I just hate those words. I really do.

And you. What do you think?

Naz I’ve never actually thought of it like that. I mean I’ve been called obese and stuff yes, but I’ve never thought to myself that I am. Well I have said to myself that I am obese because I heard people say to me that you obese and called me overweight, but I’ve never done what she’s done like [laughs].

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Sara was called ‘a little fatty’ as a child so always avoids this kind of language with her…

Age at interview 47

Gender Female

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Also I know, I hear in my head still things that my mother used to say when I was a teenager. And I look at, photos, I grew up thinking I was quite fat and I look at photographs of myself as a teenager and there’s no way I was ever. And my mother always felt she was doing it with love and therefore it was fine but she’s German and she would call me Dickerchen’ which basically means little fatty.

If it was sunny she’d say, Have you got sun cream on your speck. Well speck is like the white fat on ham. And I was never fat, you know [laughs]. And I’d, but the, I was getting these words used and it, I was wearing big baggy clothes to cover up all my fat but I wasn’t fat [laugh] and I was worrying about food and about my weight and my fat, you know, what size I was and I didn’t need to. And it’s taken me a long time as an adult to actually just relax.

And, you know, there are times when I’ thinking, you know, got a bit of a roll there. I’d rather not have it but I’m ok [laugh]. it’s ok [laugh]. And so I never ever have used words like that. I’ve never called her chubby’ or, you know. it’s justBut I don’t know sometimes when you become too conscious about these things maybe you do it all wrong because you’re trying to overcompensate the other way. I don’t know.

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A few did not mind the word ‘obese’ being used as a general description.

Rachael would think of herself as ‘obese’ even if she lost weight because it’s a label she’s always been associated with.

Gender Female

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That is definitely a word that I’d use to describe myself, ‘obese. Especially like because when I went to go to the dieticians when I was younger, because of the way it works and it’s all in like a big wave. When you’d marked me on it, I’d be nearly off the scale, when I was a kid. So you know it’s kind of that’s something that I’ve always remembered that I have always been ridiculously obese.And to be honest I don’t know even if I lost weight, I’d still think myself as obese, because it is something that I have always been associated with.You know. There’s being ‘overweight’ and there’s being ‘obese. And I know I’m obese. You know. There’s no two ways about it to be honest.

I once did get a compliment because – I can’t remember what we were talking about but he said and I went, Oh yeah, well that’s because I’m really fat. And he went, From where I’m from, you’d be thin. I was like… [but] he meant that as a compliment. And I thought, Okay. But you know it’s just something that you do. I do consider myself to be obese. And I think I’d have to lose a fair bit of weight just to be considered overweight.

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Dee says that using words like ‘big’ just ‘beats around the bush.

Age at interview 47

Gender Female

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Well, I actually think if you’re fat, you’re fat and if you’re skinny, you’re skinny, if you’re obese then it’s a medical term isn’t it? And it means that you’re obese, it means your body mass index is over a certain amount and you’re obese as it were, so to me it’s just a way of describing the sort of way that the person is without being very ‘right on’ as it were I suppose.

If we say that a person’s ‘big’, it’s probably just a slightly softer way of saying it as it were. But if someone’s fat then, you know you’re fat aren’t you? You’ve got excess weight, no matter which way you look at it it’s the same thing, it’s fat, it’s excess weight. You’re big, you know. ‘Big’ doesn’t always describe it anyway does it really? Because you can be big, but you can have big feet or big shoulders, or you can have big thighs or something like that, but you might still be the right proportion for your height, but just big in certain areas as it were. But if you’re fat, that kind of describes that you’re overweight, that you’re overweight. But it’s not very nice, people don’t like it I suppose… and I suppose it could be seen as being derogatory in some way, and that, but I don’t see it as derogatory.

Just like when people tell me I’ve got a fat belly and I have got a fat belly, but it is a fat belly, there’s no other way of describing it, it’s fat – you know – it’s excess as it were but I don’t know – maybe I’m not ‘right on. I try my hardest not to be [right on] actually because I get a bit fed up with it because it beats around the bush and everybody knows what everybody’s trying to say really but they’re sort of not saying what they want to say – just trying to sort of protect the other person to some degree.

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Some young people said they knew they were morbidly obese and they found the use of those words scary and worrying. Several found the labels discouraged them from losing weight; they wondered why they would bother just to get from ‘morbidly obese’ to ‘obese’.

Vicki would rather be called ‘every name under the sun’ than ‘obese.

Gender Female

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I’d rather be called like every name under the sun than be called obese. Just because I just think it’s a disgusting word. And I, but I know it’s like the correct terminology for like being overweight, like well quite a lot overweight, but I just really don’t like the word, and I, and I because I know it means like more overweight than overweight, like, and I know that I am obese, and it just, oh, I’d rather be called overweight, or fat, than obese. But although knowing I’m obese, I’d rather not be told it. Like, you know, it’s one of those things, I’d, I refer to myself as fat, but if someone else called me fat I’d be like, Oh, thanks. But I wouldn’t really let on, I would, I’d just be like, Yeah I know.

Morbidly obese is the scariest one, horrible, horrid. Just morbid is just oh, I just don’t like the word either, and what it means and it’s just, and I don’t know, I don’t know what it is about the words obese, I really don’t know what it is, but I just really, really, really gets to me that word. If someone was to say, call me obese in a serious way, I probably would just cry in front of them, but whereas if someone just called me fat or overweight I’d just be like, Yeah, I know. But I, I guess it’s because fat’s sort of the word you throw around as an insult isn’t it? And overweight is like the polite way of saying fat. But obese is just scary. Like when you’re obese you know you’re in trouble.

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Huw says being labelled according to the BMI is horrible.

Gender Male

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I was diagnosed as being morbidly obese before I started this diet, and I’m now super obese, which I really hate, because it makes you feel so horrible about yourself, I mean, it’s a shock to the system and it makes you want to do something about it, but it’s just labelling someone, it’s like labelling someone as like, I don’t know, diabetic or something. And it’s of, but its, with less you can do about it. If you, if you’re not doing anything and you’re living a lifestyle where you are home takeaway five days a week, you don’t cook from first, from, you don’t cook from first principles, and it’s that, that then that that would be shock you’d need to cut down and actually do something about it, but when you’re already doing all that, and you’re going to gym and you’re trying to lose weight, and you have been trying to lose weight for years, that’s not what you need. You don’t need to be labelled as morbidly obese, because that’s so depressing, and you’re just like, well I’ve been trying, why bother.

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Holly dislikes the phrase ‘morbidly obese’ because it doesn’t help her confidence.

Gender Female

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Did you actually work out your BMI then?

Yeah. Can’t remember what it is now, but it was in the, the end of the scale, you know the big red one that says you really need to do something now. And it’s been jumping between the last couple I think, and my doctor looked at it the other day, I think it was in the lesser one, whereas before it was in the larger one. But I don’t pay attention to it that much.

Why do you not want to pay attention to that?

Because I’m in the ‘morbidly obese’ category, and I wouldn’t consider myself that, I would say that I’m ‘overweight’, and I think ‘morbidly obese’ is not the term to put on it. And I think even if someone was that size because if someone is that size they know that they’re overweight, they’re not going to be that stupid – but to say you are ‘morbidly obese’ isn’t a nice way to go about it. So I think because you know if you go down the scales there’s ‘underweight’ which I think someone these days would be quite glad to be called underweight because it means they’re so skinny, but there is no derogatory way to say that you’re underweight, if that makes sense?

Yes.

It’s alright being skinny whereas before that would’ve been a compliment. So that’s why I don’t pay attention to them.

But can you tell me what the problem is with the term ‘morbidly obese’ and why you don’t want to be in that category?

I just think it’s the way it’s put, because as I was saying, there are people who are like me know that they’re fat, they know that they need to lose weight, but it’s just not a pleasant phrase. So I think if it was put differently maybe I might have paid more attention to it, and I know it’s sort of shock tactics and things, but still it’s, it doesn’t help the confidence if you’re called morbidly obese.

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Most parents preferred to focus on their child’s good points. They didn’t want to damage their son or daughter’s self-confidence even when they knew s/he had become much larger than their friends and siblings. Not everyone felt like this; one mother said she believed children and their parents needed to be ‘shocked’ into taking drastic action over eating, exercise and health.