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.
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