NYT: Is BMI a scam?

[Anonymous]

BMI is fine as a general indicator. A Dr can tell by looking at you if you are overweight or not. If you have a BMI of 26 and are a power lifter, it is pretty obvious

[Anonymous]

Anonymous wrote:I have mixed feelings about this. I think all these things are true:

1) Doctors rely too much on obesity being the be all end all health problem source of a fat person and this results in bad care

2) For people in the 'normal' BMI category it can mask health problems unrelated to weight because they believe they are healthy

3) For people who are 36 BMI (like I was!) it can be a useful to be a really be a sure sign that you need to do something about it and for me personally I used the 'BMI doesn't matter' to blow past a lot of numbers I should have cared about.

So like it isn't the be all and end all but I think it has its uses.

Yes to all of this. The BMI weight range for "normal weight" for my height spans 45 lbs. That's not really a useful measure of health IMO.

I will say I have never had any doctor talk about my BMI, or even my weight for that matter, even though I have been overweight and even obese according to BMI.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:"This explains why muscular athletes often have high B.M.I.s despite having little body fat" is only true for men. There's a literature on this. Women can't put on enough muscle naturally to have high BMIs without also having high body fat.

In general, whether this is an accurate indicator is separate from whether it makes sense to focus on. I'd argue it doesn't make tons of sense to focus on, but the reason I'd give is one that they don't even mention, which is that long-term, significant weight loss is really hard. Even if being overweight is making you unhealthy, if you're not going to change that and it's really stressful to think about, then it's better to focus on things you can change. But that doesn't mean we have to say it's a bad indicator, and that it makes people feel bad is totally separate from whether it has predictive value. (And the bit about "People who have felt discriminated against because of heavier weight are also about 2.5 times more likely to have mood or anxiety disorders" suggests a pretty obvious alternative causal explanation.)

But it IS a bad indicator at the individual level. Did you see the other thread where people are splitting hairs over whether a 5'4" woman who wants to get back to 112 has disordered thinking because 112 is either 1-2 or 3-4 pounds away from being underweight? This makes absolutely no sense at all, but people think the idea of being underweight/overweight based on BMI is some super scientific measure. It's not, and it means very little.

Just because something is being misused doesn't mean it doesn't have explanatory value in another context. And with any continuous variable that we split into discrete categories, there's going to be some amount of arbitrariness close to the lines. Is "18" really that different from "19"? Of course not. But if someone shows up with a BMI of 17 in your office, there are questions you should be asking them that you would not ask someone at a 'normal' weight, not because there's no overlap between the answers to those questions between underweight and normal-weight people, but because it's a matter of probability.

There's plenty of evidence that doctors treat obese people horribly, so even in a medical context BMI isn't really being used in a productive way. Why can't doctors just look at more specific markers of health? People with high BMIs can be healthy but instead they have their medical issues ignored and they get treated as though any issue they have is their own fault for eating too much.
From the article:

. In a 2016 study of more than 40,000 adults in the United States, researchers compared people’s B.M.I.s with more specific measurements of their health, like their insulin resistance, markers of inflammation and blood pressure, triglyceride, cholesterol and glucose levels. Nearly half of those classified as overweight and about a quarter of those classified as obese were metabolically healthy by these measures. On the other hand, 31 percent of those with a “normal” body mass index were metabolically unhealthy.

That's incredibly informative for an indicator that you can take in under a minute, non-invasively, and that you don't need someone with medical training to administer. I'd use that as evidence for the usefulness of BMI, not against it -- and I'd bet that, combined with age and sex, which we also collect, it's even more informative. We don't always look at specific markers of health because they are more invasive, more expensive, and more time-consuming to collect, but one of the ways we can and should use BMI is when to decide to collect that additional information. But even BMI by itself is useful - for instance, there are medications that are less effective if you're overweight or obese, and you're going to get different recommendations about weight gain during pregnancy.

If we were going to replace BMI with something else that was better, that would be one thing. But that seems unlikely to me. And it's not like if you remove this as a category that doctors are going to stop stereotyping overweight and obese people and blaming their medical problems on their weight. Not measuring BMI isn't going to remove their ability to notice which of their patients are heavier.

Yes actually we should tell doctors that BMI is not a great indicator. Just because the medical profession is terrible at treating obesity and obese people doesn't mean they can't be better.

Doctors will never give two sh*ts about obese patients. It's hopeless.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:"This explains why muscular athletes often have high B.M.I.s despite having little body fat" is only true for men. There's a literature on this. Women can't put on enough muscle naturally to have high BMIs without also having high body fat.

In general, whether this is an accurate indicator is separate from whether it makes sense to focus on. I'd argue it doesn't make tons of sense to focus on, but the reason I'd give is one that they don't even mention, which is that long-term, significant weight loss is really hard. Even if being overweight is making you unhealthy, if you're not going to change that and it's really stressful to think about, then it's better to focus on things you can change. But that doesn't mean we have to say it's a bad indicator, and that it makes people feel bad is totally separate from whether it has predictive value. (And the bit about "People who have felt discriminated against because of heavier weight are also about 2.5 times more likely to have mood or anxiety disorders" suggests a pretty obvious alternative causal explanation.)

But it IS a bad indicator at the individual level. Did you see the other thread where people are splitting hairs over whether a 5'4" woman who wants to get back to 112 has disordered thinking because 112 is either 1-2 or 3-4 pounds away from being underweight? This makes absolutely no sense at all, but people think the idea of being underweight/overweight based on BMI is some super scientific measure. It's not, and it means very little.

Just because something is being misused doesn't mean it doesn't have explanatory value in another context. And with any continuous variable that we split into discrete categories, there's going to be some amount of arbitrariness close to the lines. Is "18" really that different from "19"? Of course not. But if someone shows up with a BMI of 17 in your office, there are questions you should be asking them that you would not ask someone at a 'normal' weight, not because there's no overlap between the answers to those questions between underweight and normal-weight people, but because it's a matter of probability.

There's plenty of evidence that doctors treat obese people horribly, so even in a medical context BMI isn't really being used in a productive way. Why can't doctors just look at more specific markers of health? People with high BMIs can be healthy but instead they have their medical issues ignored and they get treated as though any issue they have is their own fault for eating too much.
From the article:

. In a 2016 study of more than 40,000 adults in the United States, researchers compared people’s B.M.I.s with more specific measurements of their health, like their insulin resistance, markers of inflammation and blood pressure, triglyceride, cholesterol and glucose levels. Nearly half of those classified as overweight and about a quarter of those classified as obese were metabolically healthy by these measures. On the other hand, 31 percent of those with a “normal” body mass index were metabolically unhealthy.

That's incredibly informative for an indicator that you can take in under a minute, non-invasively, and that you don't need someone with medical training to administer. I'd use that as evidence for the usefulness of BMI, not against it -- and I'd bet that, combined with age and sex, which we also collect, it's even more informative. We don't always look at specific markers of health because they are more invasive, more expensive, and more time-consuming to collect, but one of the ways we can and should use BMI is when to decide to collect that additional information. But even BMI by itself is useful - for instance, there are medications that are less effective if you're overweight or obese, and you're going to get different recommendations about weight gain during pregnancy.

If we were going to replace BMI with something else that was better, that would be one thing. But that seems unlikely to me. And it's not like if you remove this as a category that doctors are going to stop stereotyping overweight and obese people and blaming their medical problems on their weight. Not measuring BMI isn't going to remove their ability to notice which of their patients are heavier.

Yes actually we should tell doctors that BMI is not a great indicator. Just because the medical profession is terrible at treating obesity and obese people doesn't mean they can't be better.

Your manager and coworkers don't know your BMI. Neither does someone interviewing you, or someone on a dating app. Overweight and obese people still get treated differently in those contexts. Collecting BMI is not what is driving this. Get rid of BMI and you just get rid of it as a predictor, where it carries useful information, not in the ways you want to get rid of it.

[Anonymous]

NASM Trainer here - BMI is not a "scam". It's a tool. It's one of many tools we use to assess a client. It doesn't provide us much information about bodybuilders, for example. But it gives us a good indication of whether the typical client is overweight, underweight, or in their ideal weight range. When we combine this information with the other data we collect, we get a good picture of overall health and fitness level.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:"This explains why muscular athletes often have high B.M.I.s despite having little body fat" is only true for men. There's a literature on this. Women can't put on enough muscle naturally to have high BMIs without also having high body fat.

In general, whether this is an accurate indicator is separate from whether it makes sense to focus on. I'd argue it doesn't make tons of sense to focus on, but the reason I'd give is one that they don't even mention, which is that long-term, significant weight loss is really hard. Even if being overweight is making you unhealthy, if you're not going to change that and it's really stressful to think about, then it's better to focus on things you can change. But that doesn't mean we have to say it's a bad indicator, and that it makes people feel bad is totally separate from whether it has predictive value. (And the bit about "People who have felt discriminated against because of heavier weight are also about 2.5 times more likely to have mood or anxiety disorders" suggests a pretty obvious alternative causal explanation.)

But it IS a bad indicator at the individual level. Did you see the other thread where people are splitting hairs over whether a 5'4" woman who wants to get back to 112 has disordered thinking because 112 is either 1-2 or 3-4 pounds away from being underweight? This makes absolutely no sense at all, but people think the idea of being underweight/overweight based on BMI is some super scientific measure. It's not, and it means very little.

Just because something is being misused doesn't mean it doesn't have explanatory value in another context. And with any continuous variable that we split into discrete categories, there's going to be some amount of arbitrariness close to the lines. Is "18" really that different from "19"? Of course not. But if someone shows up with a BMI of 17 in your office, there are questions you should be asking them that you would not ask someone at a 'normal' weight, not because there's no overlap between the answers to those questions between underweight and normal-weight people, but because it's a matter of probability.

There's plenty of evidence that doctors treat obese people horribly, so even in a medical context BMI isn't really being used in a productive way. Why can't doctors just look at more specific markers of health? People with high BMIs can be healthy but instead they have their medical issues ignored and they get treated as though any issue they have is their own fault for eating too much.
From the article:

. In a 2016 study of more than 40,000 adults in the United States, researchers compared people’s B.M.I.s with more specific measurements of their health, like their insulin resistance, markers of inflammation and blood pressure, triglyceride, cholesterol and glucose levels. Nearly half of those classified as overweight and about a quarter of those classified as obese were metabolically healthy by these measures. On the other hand, 31 percent of those with a “normal” body mass index were metabolically unhealthy.

That's incredibly informative for an indicator that you can take in under a minute, non-invasively, and that you don't need someone with medical training to administer. I'd use that as evidence for the usefulness of BMI, not against it -- and I'd bet that, combined with age and sex, which we also collect, it's even more informative. We don't always look at specific markers of health because they are more invasive, more expensive, and more time-consuming to collect, but one of the ways we can and should use BMI is when to decide to collect that additional information. But even BMI by itself is useful - for instance, there are medications that are less effective if you're overweight or obese, and you're going to get different recommendations about weight gain during pregnancy.

If we were going to replace BMI with something else that was better, that would be one thing. But that seems unlikely to me. And it's not like if you remove this as a category that doctors are going to stop stereotyping overweight and obese people and blaming their medical problems on their weight. Not measuring BMI isn't going to remove their ability to notice which of their patients are heavier.

Yes actually we should tell doctors that BMI is not a great indicator. Just because the medical profession is terrible at treating obesity and obese people doesn't mean they can't be better.

Your manager and coworkers don't know your BMI. Neither does someone interviewing you, or someone on a dating app. Overweight and obese people still get treated differently in those contexts. Collecting BMI is not what is driving this. Get rid of BMI and you just get rid of it as a predictor, where it carries useful information, not in the ways you want to get rid of it.

It carries useful information maybe for White men. Much less so for other groups. Just because it's not the only problem with how our society treats overweight and obese people doesn't mean it's not a problem. It's a made up statistic treated like it's based on something and it's not.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:"This explains why muscular athletes often have high B.M.I.s despite having little body fat" is only true for men. There's a literature on this. Women can't put on enough muscle naturally to have high BMIs without also having high body fat.

In general, whether this is an accurate indicator is separate from whether it makes sense to focus on. I'd argue it doesn't make tons of sense to focus on, but the reason I'd give is one that they don't even mention, which is that long-term, significant weight loss is really hard. Even if being overweight is making you unhealthy, if you're not going to change that and it's really stressful to think about, then it's better to focus on things you can change. But that doesn't mean we have to say it's a bad indicator, and that it makes people feel bad is totally separate from whether it has predictive value. (And the bit about "People who have felt discriminated against because of heavier weight are also about 2.5 times more likely to have mood or anxiety disorders" suggests a pretty obvious alternative causal explanation.)

But it IS a bad indicator at the individual level. Did you see the other thread where people are splitting hairs over whether a 5'4" woman who wants to get back to 112 has disordered thinking because 112 is either 1-2 or 3-4 pounds away from being underweight? This makes absolutely no sense at all, but people think the idea of being underweight/overweight based on BMI is some super scientific measure. It's not, and it means very little.

Just because something is being misused doesn't mean it doesn't have explanatory value in another context. And with any continuous variable that we split into discrete categories, there's going to be some amount of arbitrariness close to the lines. Is "18" really that different from "19"? Of course not. But if someone shows up with a BMI of 17 in your office, there are questions you should be asking them that you would not ask someone at a 'normal' weight, not because there's no overlap between the answers to those questions between underweight and normal-weight people, but because it's a matter of probability.

There's plenty of evidence that doctors treat obese people horribly, so even in a medical context BMI isn't really being used in a productive way. Why can't doctors just look at more specific markers of health? People with high BMIs can be healthy but instead they have their medical issues ignored and they get treated as though any issue they have is their own fault for eating too much.
From the article:

. In a 2016 study of more than 40,000 adults in the United States, researchers compared people’s B.M.I.s with more specific measurements of their health, like their insulin resistance, markers of inflammation and blood pressure, triglyceride, cholesterol and glucose levels. Nearly half of those classified as overweight and about a quarter of those classified as obese were metabolically healthy by these measures. On the other hand, 31 percent of those with a “normal” body mass index were metabolically unhealthy.

That's incredibly informative for an indicator that you can take in under a minute, non-invasively, and that you don't need someone with medical training to administer. I'd use that as evidence for the usefulness of BMI, not against it -- and I'd bet that, combined with age and sex, which we also collect, it's even more informative. We don't always look at specific markers of health because they are more invasive, more expensive, and more time-consuming to collect, but one of the ways we can and should use BMI is when to decide to collect that additional information. But even BMI by itself is useful - for instance, there are medications that are less effective if you're overweight or obese, and you're going to get different recommendations about weight gain during pregnancy.

If we were going to replace BMI with something else that was better, that would be one thing. But that seems unlikely to me. And it's not like if you remove this as a category that doctors are going to stop stereotyping overweight and obese people and blaming their medical problems on their weight. Not measuring BMI isn't going to remove their ability to notice which of their patients are heavier.

Isn’t there a proposal out there for waistline over or under 30”?

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:"This explains why muscular athletes often have high B.M.I.s despite having little body fat" is only true for men. There's a literature on this. Women can't put on enough muscle naturally to have high BMIs without also having high body fat.

In general, whether this is an accurate indicator is separate from whether it makes sense to focus on. I'd argue it doesn't make tons of sense to focus on, but the reason I'd give is one that they don't even mention, which is that long-term, significant weight loss is really hard. Even if being overweight is making you unhealthy, if you're not going to change that and it's really stressful to think about, then it's better to focus on things you can change. But that doesn't mean we have to say it's a bad indicator, and that it makes people feel bad is totally separate from whether it has predictive value. (And the bit about "People who have felt discriminated against because of heavier weight are also about 2.5 times more likely to have mood or anxiety disorders" suggests a pretty obvious alternative causal explanation.)

But it IS a bad indicator at the individual level. Did you see the other thread where people are splitting hairs over whether a 5'4" woman who wants to get back to 112 has disordered thinking because 112 is either 1-2 or 3-4 pounds away from being underweight? This makes absolutely no sense at all, but people think the idea of being underweight/overweight based on BMI is some super scientific measure. It's not, and it means very little.

Just because something is being misused doesn't mean it doesn't have explanatory value in another context. And with any continuous variable that we split into discrete categories, there's going to be some amount of arbitrariness close to the lines. Is "18" really that different from "19"? Of course not. But if someone shows up with a BMI of 17 in your office, there are questions you should be asking them that you would not ask someone at a 'normal' weight, not because there's no overlap between the answers to those questions between underweight and normal-weight people, but because it's a matter of probability.

There's plenty of evidence that doctors treat obese people horribly, so even in a medical context BMI isn't really being used in a productive way. Why can't doctors just look at more specific markers of health? People with high BMIs can be healthy but instead they have their medical issues ignored and they get treated as though any issue they have is their own fault for eating too much.
From the article:

. In a 2016 study of more than 40,000 adults in the United States, researchers compared people’s B.M.I.s with more specific measurements of their health, like their insulin resistance, markers of inflammation and blood pressure, triglyceride, cholesterol and glucose levels. Nearly half of those classified as overweight and about a quarter of those classified as obese were metabolically healthy by these measures. On the other hand, 31 percent of those with a “normal” body mass index were metabolically unhealthy.

That's incredibly informative for an indicator that you can take in under a minute, non-invasively, and that you don't need someone with medical training to administer. I'd use that as evidence for the usefulness of BMI, not against it -- and I'd bet that, combined with age and sex, which we also collect, it's even more informative. We don't always look at specific markers of health because they are more invasive, more expensive, and more time-consuming to collect, but one of the ways we can and should use BMI is when to decide to collect that additional information. But even BMI by itself is useful - for instance, there are medications that are less effective if you're overweight or obese, and you're going to get different recommendations about weight gain during pregnancy.

If we were going to replace BMI with something else that was better, that would be one thing. But that seems unlikely to me. And it's not like if you remove this as a category that doctors are going to stop stereotyping overweight and obese people and blaming their medical problems on their weight. Not measuring BMI isn't going to remove their ability to notice which of their patients are heavier.

Isn’t there a proposal out there for waistline over or under 30”?

The same criticisms mostly apply. It's still stigmatizing oppressed people by telling them they could improve something about themselves.

[Anonymous]

BMI is a rough guideline - it is not a precise determiner, and isn't helpful for people who are physically active and likely have greater muscle mass.

[Anonymous]

Anonymous wrote:BMI is a rough guideline - it is not a precise determiner, and isn't helpful for people who are physically active and likely have greater muscle mass.

LOL. People telling themselves that because they lope around the block or on a treadmill for 30 minutes every other day they likely have a greater muscle mass.

BMI isn't the end all and be all (most people already know if they are too skinny or too fat), but the muscle mass it takes to throw off the charts is not even obtainable by most desk jockeys.

[Anonymous]

My 5 year old who is so skinny that he can’t keep his pants up was at the pediatrician last week and his BMI was high. She said not to worry about it. BMI is such a rough measure that it doesn’t tell you much, especially in kids.

[Anonymous]

Anonymous wrote:

Anonymous wrote:BMI is a rough guideline - it is not a precise determiner, and isn't helpful for people who are physically active and likely have greater muscle mass.

LOL. People telling themselves that because they lope around the block or on a treadmill for 30 minutes every other day they likely have a greater muscle mass.

BMI isn't the end all and be all (most people already know if they are too skinny or too fat), but the muscle mass it takes to throw off the charts is not even obtainable by most desk jockeys.

PP trainer here - It really only comes into play with the serious body builder. You can tell by looking at them that using BMI won’t be accurate. There are other ways to measure their body composition. Unless you are a power lifter spending hours in the gym, BMI is a solid tool when combined with other data. Being “physically active” is awesome. But your BMI isn’t going to change much by running, walking, yoga, etc.

[Anonymous]

Anonymous wrote:I have mixed feelings about this. I think all these things are true:

1) Doctors rely too much on obesity being the be all end all health problem source of a fat person and this results in bad care

2) For people in the 'normal' BMI category it can mask health problems unrelated to weight because they believe they are healthy

3) For people who are 36 BMI (like I was!) it can be a useful to be a really be a sure sign that you need to do something about it and for me personally I used the 'BMI doesn't matter' to blow past a lot of numbers I should have cared about.

So like it isn't the be all and end all but I think it has its uses.

It isn't so much that it results in bad care, but obesity IS just about the worst chronic health problem to have because it negatively affects nearly all of your other systems-over the long term. It puts strain on your heart, lungs, joints, builds fatty deposits around organs so they don't function as well, disrupts hormones, circulation, and on and on. Even something like a minor hemorrhoid is a lot harder to treat on an obese person. But harder to treat I mean the treatments approved for use are just not as effective- or in some cases- not effective at all due to obesity. What may seem like "bad care" is often that people can't get the therapeutic results they want due to the obesity.

[Anonymous]

Anonymous wrote:

Anonymous wrote:BMI is a rough guideline - it is not a precise determiner, and isn't helpful for people who are physically active and likely have greater muscle mass.

LOL. People telling themselves that because they lope around the block or on a treadmill for 30 minutes every other day they likely have a greater muscle mass.

BMI isn't the end all and be all (most people already know if they are too skinny or too fat), but the muscle mass it takes to throw off the charts is not even obtainable by most desk jockeys.

maybe we should be using calipers more widely, that way no muscle mass will come into play. Im sure people wouldn't howl about how degrading that is

[Anonymous]

This is one where multiple things can be true - BMI is good on population levels but not so much individuals. HOWEVER discarding BMI entirely is doing a disservice to our society at large, which is struggling under a huge obesity epidemic that isn't helped by normalizing lifestyle choices that keep people fat. So, don't focus on BMI but focus on good eating and weight choices.