More than 75% of US adults may meet criteria for obesity under new definition: Study

[BumRushDaShow]

Source: The Guardian

December 29, 2025, 1:23 PM


A new definition of obesity could nearly double the prevalence of U.S. adults with the condition, according to a study published Monday.

For decades, doctors have relied on body mass index (BMI) -- a tool that uses height and weight to estimate body fat -- to determine obesity.

A team of researchers from Beth Israel Deaconess Medical Center, Harvard University, Yale University and Yale New Haven Health, found that BMI alone may significantly underestimate how many U.S adults have obesity.

Using a new definition that includes waist-based measurements, the team found that more than 75% of adults may meet criteria for obesity compared to 40% when using BMI alone.

Read more: https://abcnews.go.com/Health/75-us-adults-meet-criteria-obesity-new-definition/story?id=128747616

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Link to JAMA study PUBLICATION - Body Mass Index and Anthropometric Criteria to Assess Obesity

[underpants]

1. I'll stick with BMI thank you. 3 links in I can't find the definition

[sinkingfeeling]

3. Here's the links to the BRI and BMI calculators.

BRI - https://www.pbrc.edu/research-and-faculty/calculators/brc.aspx

BMI - https://www.nhlbi.nih.gov/calculate-your-bmi

[underpants]

8. Okay. I stay at 220 for the BMI

I’m not asking you to do anything but I don’t see the actual BRI calculator.

[sinkingfeeling]

15. Starts with demographics.

[SpankMe]

25. Both of these say I'm fat. Kida sucks. n/t

[Vinca]

2. Uh huh. Why do smell the whiff of big pharma around the edges? I love when they do this. It's not the first time

they've changed a standard when the obvious outcome means doctors will recommend more expensive drugs to their patients.

[TheRickles]

6. Exactly. Maybe someday the focus can embrace lifestyle changes like nutrition, exercise and stress management.

Those options are effective but not patentable, so the profit motive won't be the driving force as it is for so much in the American health care industry.

[yardwork]

9. The Trump admin is all about the new weight loss drugs.

It's RFK, Jr's solution to everything.

[NotHardly]

10. Has RFKjr seen Trump?

[yardwork]

13. I can't explain it either.

[NickB79]

11. This has been known for years

There have been studies going back a decade that found this. This one is from 2011.

https://www.nature.com/articles/ijo2011100

We found that 29% of subjects classified as lean and 80% of individuals classified as overweight according to BMI had a BF% within the obesity range.

The primary reason is that people who score as a "healthy weight" on the BMI scale, and don't appear obese, are in reality severely under-muscled due to lack of physical activity.

It's ironic that people have been claiming that BMI isn't accurate for years. When more accurate measurements are included that show that BMI actually underestimates obesity, that too is rejected. It's almost like a sizeable portion of the population just wants to ignore the serious health effects of obesity because it's uncomfortable to address.

[ananda]

17. What that weird drug does to people really creeps me out.

Ozempic or something like that.

It makes them look anorexic.

I was never fat, but when I started gaining weight
later in life, I switched my diet to avoid diabetes
and other problems. It's called the Zone diet,
and boy does it work.

And I look totally normal to boot.

[slightlv]

21. Some of the effects now being

seen are worse than just looking anorexic. One of the big issues i have is it's a lifetime drug. As soon as you stop the drug the weight comes back. Healthy weight doesn't have a black and white answer, which is one of the reasons the US won't discover "the answer".

I was obese all my life. Tried every diet out there, counted calories and worked out until all I did was go to work, count calories, and exercise. Nothing helped long term. One day, my rheumatologist put me on Lyrica and I gained 20 pounds in one month, despite not changing my... what would be called "good" habits... even exercising thru fibro and lupus pain. Next visit Doc took me off the drug, of course. I immediately began dropping weight. I went from over 200 lbs to 86... and I have to fight to keep that number up. Like I said, there is no black and white answer. I'm sure the Lyrica was only coincidentally connected to my weight loss... but I also personally knew another who had my exact consequences. Why? No idea. The only thing she and I had in common besides being female is we're both short.

Finding mechanisms that help people are going to end up being personal to each, IMO. But we want a one size fits all, preferably a pill we can swallow once a day. And I honestly don't believe that will ever happen. But this is the US and we no longer believe in Science... sigh.

[Old Crank]

35. Insurance companies

They have ideal weights v heights for man and women.
Had them for decades. Help to set rates because they know that too much weight reduces life span and increases types of disease. The tables for ideal make you quite lean. Here I've included teh old Met life tables. There is also a measurement for frame size.
My max weight should be under 200 LBs. for the large frame. I haven't measured my elbow.

http://www.assessmentpsychology.com/metlife.htm

BTW I am borderline obese by the BMI/height standard.

[Vinca]

36. Few of us meet the ever-changing standards, but here we are. Living and breathing. I'm about to turn 77.

[Old Crank]

38. 75 in March

I did note that current weight standards seem to be close to 20 pounds heavier for my height cohort than in 1983.

I would say that having cut 13 kilos I do move better than I did last year at this time. My goal is another 10 kilo and that will still keep me as over weight.

[Bettie]

43. (Warning: Ranty) Fat people being unhealthy is not universal any more than

thin people being healthy is.

I am fat. According to those charts, I'm....dead, obviously, of the scourge of fat. Oh, and I have the beginnings of osteoarthritis in my joints, like all four of my grandparents and both my parents...thin and fat.

My only other health issue normally is slightly elevated cholesterol. I take a minimal dose of a statin and I'm good to go.

I was in a car accident on the 19th, so right now, not so healthy, because I am injured, but I am strong and, yes, fat. The PT people and nurses kept commenting on how strong my legs and core are....and yet, I am very fat. The kind of fat that most people here would look at and assume I wear a red hat and am not very bright.

The not very bright thing could be up for debate on any given day.

Most of the people who "look healthy'...which is based solely on the fact that they are thin, have many more health issues than I do.

Right now, I am having some walking trouble....because my right side got hit dead-on by another car. My right hip took a direct hit, so I'm having trouble with that. I'll get past it and I'll admit, I'm being a giant baby about it, but I'm hauling myself up (we do have a wheelchair, not because I can't do the walker, but because our bathroom is 55 feet from where I am sleeping and I can't do stairs yet...seems that a 100 foot round trip to the bathroom was not what PT envisioned when they sent me home). Sorry I digress, I'm not entirely myself right now.

Nearly everyone I know is on some form of GLP1. One of my friends (my best friend for over 40 years) was on one that mentions a specific kind of cancer in the perinium in the warnings on its ads. She's dead now...but she died thinner than she had been in her adult life, so I guess that's a win in terms of how our society functions. Personally, I don't trust them any more than I have trusted any of the weight loss "miracles" on the market.

Remember Phen Fen? Lost a friend to that one... Weight Watchers and all the other diet snake oil? Lose....body adjusts to fewer calories, makes it easier to gain it back and more, then, you end up with disordered eating. For years, I wouldn't eat a simple piece of toast, because of weight watchers...or I'd make a lovely meal and sip a cup of salt-free chicken broth while everyone else ate the delicious food I had prepared.

Weight loss surgery....of the many people I know who have had that, all have had some kind of complication afterward, the ones who got it the longest ago are the closest to their beginning weights again, several with major addiction issues, because when you can't eat food, alcohol makes you feel like you have something.

People are individuals and most of the drama around people's weight isn't about health.

You don't know what someone's health is like by looking at them from a distance...it's about aesthetics. I'm never going to meet those aesthetics. I'm tall, broad, big...I look like the women in my grandfather's family going back to the earliest pictures we have from the mid 19th Century. They were big women, tall, broad of shoulder, with large bellies once they had kids. Nothing dainty about my people.

But sure, my "max weight" by these tables is 165....never going to happen, unless I get some kind of terrible disease that wastes me away.

Sorry Old Crank....your post was where my thoughts bubbled up! Not directed at you personally!

[angrychair]

4. BMI is junk science

There is absolutely no scientific evidence to support BMI as an accurate assessment of a "healthy" weight.
My spouse and I are perfect examples. Despite appearances, our blood chemistry is perfect and heart, lungs, liver and kidneys are functioning normally. Leg and feet joints are a little beat up to be fair but that's it and mine is mostly due to a lot of hiking, walking and falling. We are otherwise in good condition, not taking any maintenance meds for things like blood sugar or high blood pressure.

The idea of using waist measurement sounds even less scientifically accurate than BMI.

[Americanme]

12. I agree.

I'm almost 64 years old. My blood pressure, cholesterol, blood sugar are all good, I work out for an hour every day, I can still run 10 miles in less than 2 hours. But that chart says my BMI is 27, overweight. Guess I can live with it.

[Skittles]

44. sounds like you are doing great

I don't think everyone was meant to be stick thin

[NickB79]

14. The correlation between obesity and health issues is unquestionable

It's conclusively tied to heart disease, joint damage, diabetes, sleep apnea and over a dozen forms of cancer.

If you don't like using BMI or waist ratios, DEXA is the gold standard for body mass composition. When it's been used in studies, it too shows far more Americans are obese than previously thought.

https://www.mdedge.com/endocrinology/article/263693/obesity/bmi-vastly-underestimates-true-obesity

CHICAGO – Twice as many U.S. adults have obesity based on assessment of their fat volume by dual-energy X-ray absorptiometry (DEXA) scan compared with measurement of body mass index (BMI), a finding that highlights the shortcomings of BMI and adds to the growing case that BMI alone should not be the default gauge for obesity.

“BMI vastly underestimates true obesity,” Aayush Visaria, MD, said at the annual meeting of the Endocrine Society.

His findings highlight that “BMI should be supplemented with other measures of obesity” for the management of individual patients, with assessments that could include a bioelectrical impedance scale or waist circumference, said Dr. Visaria, a researcher at Rutgers Robert Wood Johnson Medical School in New Brunswick, N.J.

[AZLD4Candidate]

24. i'm 6'2", 265 lbs and 14% body fat. According to BMI, I am obese.

So is Stone Cold Steve Austin, Ronnie Coleman, and NFL HOF ILB Ray Lewis.

[NickB79]

41. And they're also at risk of many of the same health problems

Sleep apnea, joint damage and heart disease are well known issues in the bodybuilding community, simply from the extra mass their bodies have to carry. Add in the rampant use of steroids and the known damage that does to the body, and bodybuilders are not the epitome of health like many assume. I'm also technically overweight at 5'7", 180 lb and 18% body fat, also because I lift and work on a farm. I had dreamed of hitting 200 lb and 15% body fat, until I realized that I'd actually be less healthy than I currently am if I did so. So I've accepted this is as big as I can safely get.

Also, those people like you listed who carry enough muscle to be technically obese are a fraction of a percent of the US population. They're extreme outliers for this issue.

[raccoon]

5. Well, Just Change back to the old definition!

:

[OC375]

7. Move More

That's 50% of it for the majority of people. That part's free. Drop the phone. Get up. Live life.

The quality, and quantities, and sometimes the circumstances behind what many of us end up regularly eating is another matter entirely...

[FakeNoose]

23. Move more and eat less

... pointing to myself as the perfect target for this advice...

[twodogsbarking]

16. So with such statistics the logical approach would be for the gov to have a plan to combat it.

Or just burn the study.

[doc03]

18. Arnold in his is prime would have been morbidly obese according to

the BMI.

[JoseBalow]

19. Stop the testing

[yonder]

20. 6'-5" @ 219 lbs coming from a loudmouth soon

[fujiyamasan]

22. BMI also isn't a very good health indicator for some ethnic groups

For example, south Asians can be overweight or obese at otherwise “healthy” BMIs. It has to do with visceral fat storage. That’s why so many from the subcontinent are considered “skinny fat”.

I’m not sure how the waist based measurement would compare, but my guess is it couldn’t any less accurate than using a BMI.

[LiberalArkie]

32. Bingo. Visceral fat is the killer. Belly fat.

I was skinny fat most of my adult life. Damned near killed me

[stopdiggin]

26. so - you redefine 'obesity' to the point where it becomes an irrelevance - and people

completely stop paying attention ...
( "because, I mean, really .. why bother?" )
And THAT'LL really help address the problem! Go team!

[Diamond_Dog]

27. Too much unhealthy, processed food is marketed at us everywhere we turn.

You can’t even go to a friggin gas station without being assaulted by racks of candy and donuts. I see people in grocery stores buying soda pop by the cart full. Breakfast cereal is ridiculously sweet. Manufacturers put sugar in everything. Restaurant portions are super sized and loaded with salt. Junk food is cheap, unhealthy, and everywhere. American food manufacturers need to accept some of the blame.

[oswaldactedalone]

28. This is correct

5 years ago, I decided that at 5’10 and 199 lbs. it was time to get serious about weight loss. As a healthcare professional, I never felt right about not presenting a healthy appearance to patients and at one point in 2016 topped out at 220 with a 40” waist.

In addition to regular brisk walking several times a week, I began using time-restricted eating 3 days/wk. so that from roughly 5pm to 7am, I consumed water but no calories for 14 hours. At first, it was difficult and somewhat stressful to go that long without eating but I stuck with it and was surprised at how effective it was. I set a goal of losing 33lbs. in 33 weeks since there were 33 weeks left in the year when I began this, and met my goal of 166lbs. on the last day of the last week.

I continued using it 3x/wk. over the next three years and maintained all of my weight loss. I changed jobs 18 months ago with a change to more normal hours so increased time restricted eating to 6 days/wk. I’m now very happy at being right in the 158-162 range and use the time restriction to stay there. BTW, my metabolic test scores are all well within normal limits.

Just as important, your physiology greatly benefits from giving your body a break from constantly having to digest food and store excess calories. I highly recommend time restricted eating as a tool to lose and control weight as well as promoting overall wellness.

[gristy]

31. This makes sense

So I think what you are doing is not eating for so long that there are no more carbs to covert to glucose and no more glycogen (in liver and muscles) to covert to glucose, so the body must then convert fat to glucose.

Good job!

[oswaldactedalone]

39. In a nutshell

that’s the whole ball of wax when it comes to all the processes involved with consuming, using, and storing calories. It’s been some time since I read about the details of insulin’s role in digestion but I do know that the development of insulin resistance is one of the side effects of eating outside an 8-10 hour window on an everyday basis.

[BidenRocks]

29. Who is going to tell Chump

he is morbidly obese?
His stated height is a lie.

[chouchou]

30. It just told me the old joke "One at a time on the scale".

Asshole...

[QueerDuck]

33. I'm not fat. I'm what they call a "bear".

[debsy]

34. I'd be a stick figure if I followed the BRI

I’m with the CW here that this is all about big $$$ for some billionaires and more stress for us commoners.

[Old Crank]

37. BMI / Height for obesity has its flaws.

It needs to be taken with a grain of salt.
Most athletes will be overweight or obese based on BMI.
Muscle is heavier than fat for the same volume. Finding your body fat percentage would be a better measure. Fat calipers or the gold standard, submerged volume. I had a scale that would give me a reading of % body fat. However I would suggest that for most Americans the BMI measurement is a reasonable starting point. If your BMI is high and you don't do anything you should go talk to your doctor and see what your body chemistry is like and work to reduce some of the fat layer. (and fat around internal organs)

[Tree Lady]

40. I started intermittent fasting last May

Because of a few lab tests going wrong way, lost 15Lbs and easily keeping off without counting calories or on a certain diet.

I eat from 12-5 or 12-6 on vacations maybe 10-6, eating at night was my bad habit and I have cured that. I need to work on less sugar and even less alcohol from few times a week to few times a month.

I plan to give up dessert and wine in January.

Once you get use to it it’s very easy lifestyle.

[maxsolomon]

42. Anyone with a gut is going to be obese under BRI.

Your gut is the last fat you'll lose.