The New York Times reported yesterday on that most tedious of topics: the fact that BMI isn't a perfect measure of obesity. And sure, it isn't. Nothing is. But I'm willing to bet it's a pretty good ballpark metric about 95% of the time.
In any case, an enormous team of specialists has spent years coming up with a new and far more complicated definition. Now, if your BMI is between 25 and 40 you have only pre-clinical obesity. In order to be considered obese, you need to also have one of these 18 conditions:
![](https://jabberwocking.com/wp-content/uploads/2025/01/blog_obesity_conditions_annotated.jpg")
Are you kidding? There's hardly a middle-aged person in the country who doesn't have at least one of these conditions. Cholesterol and blood pressure alone account for roughly 50% of the population—probably more among people with BMIs above 30.
So what does all this extra complexity buy us? What percent of the population with a BMI over 30 will now be considered not obese? Is it enough to make this all worth it?
I have my doubts, though I'd like to see the relevant data. For my money, though, quit fighting it. Unless you're a bodybuilding stud, the odds are high that if your BMI is higher than 30 then you're overweight. If you don't feel like doing anything about it, fine. But there's no point in desperately looking for a loophole that will allow you to deny reality.
I do endorse any changes that will stop the medical profession's resort to using simple quantitative tests to diagnose serious illnesses. Relying on a single crude blood test to decide "Yes you are/no you're not suffering from type 2 diabetes" is the worst example.
But obesity isn't a disease. It's a condition that makes it more likely you'll acquire any number of health problems from hypertension to worn knee cartilages. And really, it's not rocket science to tell someone they're too fat. We do it with dogs all the time: can you feel their ribs? See a well-defined waist? Is there a tight abdominal tuck? Any negative answers mean the dog's too fat.
It's easy to tell if people are overweight to the point of it endangering their health by simple observation. Pseudo-scientific taxonomies simply bring medical science into disrepute.
Well, in my mind, the great appeal of BMI was that it was a height/weight chart for everyone in a single number. As such, it would have all the drawbacks of conventional ht/wt charts, at least, but for the clinician, was just a simple calculation.
On the other hand, because people now do not get to claim that they are "big boned", that adds an extra round of hate.
Similarly, BMI is very, very easy for actual regular humans to assess. I can measure my weight at home (and my height doesn't change very much), so BMI is easy to evaluate.
But, do I have microalbuminuria with (or without?) reduced eGFR? That's less something I can check for myself.
I think the idea is to shut up the people yammering about healthy obesity.
But I agree. It isn't worth the trouble. Tell them "STFU! You are fat and you should not be 'body positive' if you're fat. Go on a diet!*
Pre-clinical obesity at a BMI of 25? Eeek!
Well, the cut-off points are somewhat arbitrary. I've read where 25 is a concession to US citizens, and that it probably should be closer to 24.
Being 100# overweight, self reporting concerns about glucose spot checks I did for a week with a family members monitor, and BP trending up into high normal range (abnormal for me and my family) were not enough for my doctor to prescribe wt. loss meds.
It took until my BP and liver values were finally abnormal.
They’re working. However as those #s normalize insurance is less and less likely to authorize maintenance use.
Insurance company policy is set by these documents. Adding joint pain and sleep apnea may allow thousands of people to get maintenance zepbound/wegovy covered. Or maybe I’m just wearing rose colored glasses.
Damn, I lost a 135 lbs for nothing?? I went from a 48.1 (morbidly obese) to 29.6 (merely overweight/borderline obese).
Even at 48.1, my insurance wouldn't cover Wegovy or anything related, so I had to go on old-fashioned Phentermine (remember phen-phen anyone?). Not gonna lie, its a hard pill to swallow that all I'd have to do is gain 5 pounds and I'd be considered clinically obese again. I have another 32 lbs to lose to be considered 'healthy' weight.
Also, I'm wondering if I should be concerned about my lowered bloodpressure. I was a 89/136 pre-weight loss and now I'm at a 70/102 post, which seems kinda overly low.
You have the numbers reversed, but that's okay.
102/70 is wonderful, very healthy! 136/89 is stage 1 hypertension.
"But there's no point in desperately looking for a loophole that will allow you to deny reality." On the other hand every day we are asked to affirm people who deny reality and it may sometimes be prudent or kind to do so.
True. If a man can identify as a woman then why shouldn't a human whale be able to identify as non-overweight?
That is the dumbest non sequitur I've seen so far this year.
In short, it pisses you off because it is true and invites consideration of the contrapositive.
Ludicrously incorrect.
It's a dumb comment, not least for reasons I think you fail to grasp.
If a "human whale" decides to identify as non-overweight, what business is it of yours? That's sort of the point, isn't it? The issue is really up to them, or maybe a matter for their closest loved ones and medical professionals. Not something that you should be opining about, or feeling like you get to decide what their "real" identity is.
I mean, ffs, do you go around yelling "Hey, check out how bald this guy is under his combover!" or "Wow, this lady is old and yet she's wearing makeup"? I'd imagine that in real-life meatspace, you probably don't. And if you do, you shouldn't, because other humans have and deserve basic human dignity, which means (and I can't believe that we have to say this here in America) that their choices about their lives are none of your fucking business.
Trump didn't like being called obese.
How many of those diagnostic criteria does Trump meet? We'll never get to know.
One hopes there will be an autopsy at some point.
I'm sure the insides will be just as disgusting as the outsides. Kind of like Corian, except ugly.
He has known hyperlipidemia and atherosclerotic calcification in his heart (and almost certainly in the polenta that has replaced his below average brain).
Polenta is good! It ranks close to my all-time favorite line on that score, where the housekeeper or nanny in Being There says Chauncey Gardner has "nothing but rice pudding between the ears." It's all in the delivery.
I think I'm going to be remembering that line a lot, again.
"So what does all this extra complexity buy us?"
Maybe it will buy support from your insurance company to get effective weight-loss drugs. What factors will the insurance companies use to approve or deny payment for the drugs? Will they just consider the immediate cost and be as resistant as possible to paying, or will they be able to take account of the reductions in obesity-related conditions which would presumably reduce their costs in the future? Maybe the drugs have other health benefits. This is a complicated actuarial problem and the data aren't completely in yet.
There must surely be better ways for patients, physicians and insurance companies to make decisions than the BMI index.
There is no great scientific validity to the value of 25, even as an average. Recent studies have suggested it is too low, even if you could rely on one number.
OTOH, I've read that 25 is too high, but was chosen as a concession to the US population. I've been at 22-23 all my adult life, and I'm far from skeletal.
This is a weird argument in that BMI tends to get things wrong for athletes, although for some reason Drum dismisses them as bodybuilding studs, which sounds like a much less positive assessment. The reason is that the extra mass is due to muscles rather than fat. So some of the healthiest people come out as obese according to BMI. His argument is that BMI gets very few people wrong. But then he claims that these exceptions will apply to very few people. Given that they are likely the same people that sounds like it should be an argument in favor of the new standard. A standard that gets obesity right in more cases would seem to be a good thing. And the change highlights that obesity is problematic because it causes various health risks, which seems like a plus as well.
Although on the other side I don't know if the conditions are as rare as Drum makes them out to be. It seems like I would be somebody who is let off the hook by the new definition, and it is certainly not because I am a bodybuilding stud. All of the weight I have to lose is in the form of belly fat. So I guess the real dispute comes down to whether somebody like me who could stand to lose lets say 30 pounds, but is not suffering any of the ailments on that list should count as obese. I would like the answer to be no, but am not sure it should be.
But it is still weird that Drum complains that the change in definition is only needed to address a small number of people who get mislabeled, and then to complain that the change only relabels a small number of people.
Abdominal fat is a risk factor for cardiovascular disease.
The issue is that many more people will pretend to themselves that they are exceptions and use this as an excuse not to get healthier.
My main concern would be that the data BMI scales are based on are likely to be overwhelmingly white people's data (quite possibly mostly male and white). Applying it to all mankind might very well produce misjudgments. Hence the new add-on as a sort of insurance and an attempt to avoid fat-shaming (which is all over the comment section here!): If somebody has none of those other symptoms they are ok. I think this is eminently reasonable.
In fact those symptoms tend to show up in combination; it's not all that complicated (plus easier and cheaper than some follow up lab test).
From Australian ABC, we learn that the current classifications were developed in a 1970s Ancel Keys study based on 12 sample groups totaling about 7400 "healthy" men. They included "American students and professionals, Italian railway workers, men from east and west Finland, Japanese farmers and fishermen, and Bantu men from South Africa."
This isn't meant to be a representative population but more a normative/prescriptive one, and one based on young-adult to, say, middle-aged, mostly physically-active men, and with sampling that seems heavily weighted toward the ectomorph-mesomorph somatotype (pun intended, and of course using a discredited classification system for the irony value). And for what it's worth-- since the measurement isn't intended to be purely population-descriptive-- when the the study was done, highly-calorie-dense foods arguably weren't as widely available or as widely consumed as they are now, especially among many of the sample groups.
My personal stake in this is a BMI oscillating just above and below 25, which used to put me on the cusp of obesity (before the scale was refined). I think I could stand to lose a few pounds, but I've never been considered obese in any other context or by anybody else. I used to think these tables were based on prison camp survivors or something.
A lot of sources are saying raw waist measurement is by itself a better indicator of predisposition to problems, at least for males. But since insurance companies demand a much higher threshold, with much more complex and quantifiable indicators, before they'll cover anything, we have to go for the multi-factor charts, I guess.
You may be thinking of the "Body Roundness Index", or BRI, which is calculated as described in
https://en.wikipedia.org/wiki/Body_roundness_index
It's reasonably complex, and "visualizes the body as an ellipse instead of a cylinder."
Interesting approach that I didn't know about, but alas, nothing so complicated or precise. What I was referring to is a cut above supermarket-tabloid stuff in who mentions it but not sophisticated enough for real medicine to use publicly-- it's just taking a tape measure to the midpoint between lowest ribs and highest bony point on the pelvis. The rule of thumb for where predisposition to problems is said to take off seems to vary in the range of 37 to 40 inches. As far as I can tell it's meant more for self-assessment than anything.
And it may be completely useful, but it's obviously too straightforward to be anything an insurance company would use, or that my doctor's office would put in print on the exam summary it gives me. A BMI by itself, otoh, is just an opaque number that looks like it could be theoretically grounded, so it's a good one for both uses.
"My personal stake in this is a BMI oscillating just above and below 25, which used to put me on the cusp of obesity (before the scale was refined)."
No. 25-30 is overweight. >30 is obese.
BMI of 25 is overweight. I'm 24 and definitely could stand to lose 10 pounds.
About time. Trying to describe something as complex as obesity by a single number is sheer folly. Obesity mainly only matters insofar as it leads to other health problems. It's those problems we should be focusing on, not a simple-minded ratio that in reality tells you next to nothing.
Obesity is not complex and is, as another commenter has pointed out, easily observable with no need for measurement. Fat people LOOK fat. It shouldn't require a BMI number, or any other number, for a person to look in a mirror and say to themselves "I'm fat; I should lose weight". Likewise, it shouldn't be at all difficult for a doctor to look at a patient and say "you're fat; you should lose weight".
Obesity matters because it leads to other health problems, which puts it in the same category as type 2 diabetes, hypertension, or high cholesterol. My doctor doesn't worry about whether my high cholesterol readings are a "disease" or not; he prescribes statins with the intent of preventing any of the related diseases. Waiting until the patient develops obesity related diseases before assisting them with weight loss is as foolish as waiting until the patient has a stroke before treating their high blood pressure.
Over 200 years ago a Belgian astronomer measured a lot of people and messed about with different ways of graphing the results
He ended up with the weight/height squared graph with a peak at 21.7
THIS is the source of the BMI target ever since then!
An actual plot of mortality/BMI has the lowest mortality at about 26
The problem is that changing your BMI is difficult - having a "target" which is too low just discourages the people who do need to lose weight
That astronomer was measuring some very skinny people. For instance for a six foot (1.83 meters) person, a body mass index of 21.7 equates to a weight of just under 160 lbs. That's pretty thin, and if that's the average or median, those on the low side would have to be very thin indeed.
Eating and living patterns in Northern Europe were really, really different 200 years ago than they are for us. No fridges (except Mom Nature's in season), very little snacking material around so not much noshing between meals, and one main meal a day for most people that was heavy on the carbs and fiber and light on meats and fats. Beer was a major food source for just about everybody, and most people needed to be moving around a lot more than most of us usually do these days.
So working- and even middle-class people tended to be skinny by our standards, except I think where cheap gin might have made some of them heavier. Otherwise being corpulent ("Rubensesque") was either a sign of income and leisure, or an occupational privilege-- think of Butterbur the innkeeper in Bree, who was around food and beer all day and tending bar for much of it and could easily lay a hand on hunks of cheese and bread whenever he felt like it (in my head I always cast Gilligan's Skipper in that part).
You can get a real sense of the difference from admittedly a little earlier period if you see founding-era clothes displayed in some museums. I remember seeing one of McHenry's suits at one of them. He wasn't abnormally small but today he'd have to get fitted in the boys' department. I don't think his jacket size was anything over a 32. Washington was considered a giant at about 6 feet tall, would barely stand out in almost any crowd today, if at all.
I think the general consensus is that fitness is more important than fatness. If you're generally fit, your weight doesn't matter that much.
If you're fat, you're NOT "generally fit".