I don’t know if this is good news or bad news, but the American population just got fatter thanks to a new definition of obesity in a study published in JAMA Open Network. If you are a “glass half full” sort of person, then the new definition might make it easier to overweight people to obtain a GLP-1-RA drug since body measurements may now be part of the definition, rather than simple reliance on BMI. The results certainly point out the health risks associated with obesity – particularly “killer fat” around the abdomen – using the anthropometric measurements.
The JAMA study describes the results of a population-based longitudinal cohort study leveraging data from the All of Us cohort. Participants with anthropometric data were enrolled between May 31, 2017, and September 30, 2023 (median follow up of 4 years). Obesity was categorized as clinical or preclinical based on organ dysfunction and/or physical limitation.
In the new framework, obesity was defined using sex and race-specific thresholds as:
- A BMI greater than 40 or a BMI above the traditional obesity threshold plus at least 1 elevated anthropometric measure
- At least 2 elevated anthropometric measures even if the BMI is below the traditional obesity threshold (“anthropometric-only obesity”)
Using the new definition, 68.6% of 301,026 individuals had obesity vs 42.9% according to the traditional definition. Compared with no obesity, the odds ratios of organ dysfunction were 3.31 (95% CI, 3.24-3.37) for BMI-plus-anthropometric obesity and 1.76 (95% CI, 1.73-1.80) for anthropometric-only obesity per the new definition. Clinical obesity conferred elevated risks of incident diabetes, cardiovascular events and all-cause mortality compared with no obesity or organ dysfunction. Preclinical obesity was also associated with increased risks of incident diabetes and cardiovascular events although to a lesser degree.
There’s an astounding prevalence of clinical obesity in patients with chronic wounds, a large percentage of whom have diabetes, cardiovascular disease, hypertension, sleep apnea, and mobility limits. It seems to me the only way to reduce the incidence of chronic non-healing wounds is to tackle obesity before the patients develop the SMPTOM of a chronic ulcer.
I found the explanation hard to follow so I created a simple instruction sheet to understand the new definition:
2025 Definition of Obesity
BMI Formula: weight (kg) ÷ [height (m)]²
Example: A person who weighs 80 kg and is 1.70 m tall → 80 ÷ (1.7 × 1.7) = BMI 27.7
How to Calculate Waist-to-Hip Ratio (WHR)
- Measure waist circumference at the midpoint between the lowest rib and the top of the hip bone(at the navel).
- Measure hip circumference at the widest part of the buttocks.
- Divide waist by hip: WHR = Waist ÷ Hip
Example: Waist 90 cm, Hip 100 cm → WHR = 90 ÷ 100 = 0.90
Compare result to the cutoffs:
- Men: WHR > 0.90 → Elevated
- Women: WHR > 0.85 → Elevated
Anthropometric Cutoffs (for adults)
| Measure | Men (Non-Asian) | Women (Non-Asian) | Men (Asian) | Women (Asian) |
| Waist circumference | ≥ 102 cm (40 in) | ≥ 88 cm (35 in) | ≥ 90 cm (35.4 in) | ≥ 80 cm (31.5 in) |
| Waist-to-hip ratio | > 0.90 | > 0.85 | > 0.90 | > 0.85 |
| Waist-to-height ratio | ≥ 0.50 | ≥ 0.50 | ≥ 0.50 | ≥ 0.50 |
| BMI threshold for obesity | ≥ 30 kg/m² | ≥ 30 kg/m² | ≥ 27.5 kg/m² | ≥ 27.5 kg/m² |
How to Determine Obesity:
- Calculate BMI using the formula above.
- Measure waist, hips, and height.
- If BMI is at or above threshold and at least one waist measure is high → Obesity.
- If BMI is below threshold but two or more waist measures are high → Obesity.
- If obesity is present, assess for health effects (hypertension, sleep apnea, fatty liver, mobility limits) to classify as Clinical or Pre-clinical Obesity.
Related posts:
- JAMA Patient Information about Obesity Medications – Caroline Fife M.D.
- The Body Roundness Index – a Better Way to Understand Obesity Than BMI? – Caroline Fife M.D.
- How Can We Tackle the Connection Between Chronic Wounds and Obesity? Is Direct-to-Consumer Obesity Medication the Answer? – Caroline Fife M.D.
- Brain Pathways, Obesity and the Wound Center – Caroline Fife M.D.
- GLP-1 RAs and Peripheral Arterial Disease? – Caroline Fife M.D.
- GLP-1 RAs and Their Possible Use for Addiction and Inflammatory Conditions? – Caroline Fife M.D.
- Elevated BMI Associated With an Increased Risk of “Long COVID” – Caroline Fife M.D.
- For Newly Diagnosed Diabetics, a New Study Suggests that “It’s About the BMI…” – Caroline Fife M.D.
- Can Losing Weight Help Protect Obese People from Serious Infection? – Caroline Fife M.D.
- Tirzepatide Improves Sleep Apnea, Based on a New Study Published in NEMJ – Caroline Fife M.D.
- Wegovy Approved by the FDA to Lower the Risk of Stroke and Heart Attack in Obese NON Diabetics – Caroline Fife M.D.
- Quality of Life in Patients with Chronic Wounds… and Yes, Our Patients are Very Sick – Caroline Fife M.D.
Dr. Fife is a world renowned wound care physician dedicated to improving patient outcomes through quality driven care. Please visit my blog at CarolineFifeMD.com and my Youtube channel at https://www.youtube.com/c/carolinefifemd/videos
The opinions, comments, and content expressed or implied in my statements are solely my own and do not necessarily reflect the position or views of Intellicure or any of the boards on which I serve.
I agree that BMI is a terrible measure of obesity. In particular, the BMI is notorious for overestimating body fat in tall people. However, I posit that this new measure is even worse.
Did Big Pharma contribute to the new definition?
This new guideline seems to imply that how much fat a person is carrying overall is irrelevant so long as they are carrying much more of that fat in the butt than in the visceral area and they are small enough. A curvaceous 5′ female could be extremely heavy for her size without meeting the new obesity definition. In contrast, our less curvaceous more muscular 5’10” female patients are all now classified as obese, even if they have very little body fat and a normal BMI (high waist circumference and waist-hip ratio). This can affect their insurance rates. The same is true for all tall men with a broad frame, regardless of their athletic build (high waist circumference and BMI).
I prefer the old, “pinch an inch” metric. If pinching the skin at the abdomen yields more than an inch of flesh separating the thumb from the forefinger, weight loss is recommend.