“BMI solely takes into consideration somebody’s top and weight. It doesn’t measure a affected person’s metabolic well being or psychological well being,” says Shelly Bar, M.D., an consuming dysfunction specialist in Santa Monica, California.
Obesity because it’s presently outlined has courted a lot controversy {that a} world fee of 56 medical doctors lately published a new definition and diagnostic standards for weight problems in The Lancet Diabetes & Endocrinology. But for a lot of healthcare suppliers who observe Health at Every Size (HAES) rules, the brand new definition of scientific weight problems is controversial.
So what does “weight problems” actually imply? Here’s what it’s good to learn about how weight problems is identified and what it does and doesn’t say about a person’s well being.
What is weight problems?
Obesity is a “critical, frequent and expensive persistent illness,” in keeping with the CDC. It is presently outlined solely by a person’s BMI.
In early 2025, a world fee endorsed by 75 medical organizations world wide printed a brand new set of diagnostic criteria for weight problems.
The new framework, which relies on particular measures of physique fats together with waist circumference and physique fats proportion, somewhat than simply physique dimension, divides weight problems into two diagnostic classes: scientific weight problems and pre-clinical weight problems.
Clinical weight problems is outlined as a “situation of weight problems related to goal indicators and/or signs of lowered organ operate, or considerably lowered potential to conduct customary day-to-day actions, equivalent to bathing, dressing, consuming and continence, straight as a result of extra physique fats,” per the proposed guidelines.
Pre-clinical weight problems is outlined as “a situation of weight problems with regular organ operate.”
How do healthcare suppliers diagnose weight problems?
Currently, anybody with a BMI of 30 or above meets the diagnostic standards for weight problems. (A BMI of 25.0 to 29.9 is taken into account obese, a BMI of 18.5 to 24.9 is taken into account a wholesome weight vary, and something under 18.5 is identified as underweight.)
Essentially, BMI is a measure of physique dimension—not physique composition, metabolic well being, or illness danger.
Accurately diagnosing weight-related well being points is far more nuanced. Providers ought to ask a affected person about life-style, household historical past, and persistent circumstances and assess cardiometabolic markers like hemoglobin A1C, ldl cholesterol, and blood strain. “[BMI] actually doesn’t inform me something a few affected person besides the extent of weight stigma that’s doubtless placed on them,” Bar says.
The new framework for diagnosing scientific weight problems makes an attempt to handle a few of these points by recognizing the constraints of BMI and advocating for a extra complete evaluation primarily based on physique fats (as measured by waist circumference, waist-to-hip ratio or a DEXA scan), extra weight, and an evaluation of different medical circumstances and well being issues. “It’s principally a repackaging of the analysis of weight problems, attempting to offer a nod to those points that advocates have been elevating, however probably not altering the basics,” says Lisa Erlanger, M.D., a board-certified household doctor, scientific professor of household medication on the University of Washington School of Medicine in Seattle, and founding president of the Association for Weight and Size-Inclusive Medicine (AWSIM).
