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.

[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.

[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.

[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.

[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...

[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