BMI is a 53-year-old metric that 58 expert researchers suggest officially needs an update — here’s what they say is the most reliable way to determine a healthy body weight.
According to , the body mass index — commonly known as “IMC” — was introduced as a body measurement system in 1972.
The BMI (Muscle Mass Index) calculates a correlational measure between height and weight to determine whether an individual is obese or living at a healthy weight.
However, in recent years, experts have increasingly criticized this widely used screening tool, stating that the BMI is a poor indicator of actual health.
A January 2025 report in the magazine The Lancetreexamined the definition of obesity as chronic illness.
Presented by the Lancet Committee on Diabetes and Endocrinology, the report suggests that BMI does not define the diseasenor does it replace clinical judgment in its identification.
In fact, the report suggests that BMI may underestimate or overestimate a person’s body fat, which hampers many patients’ health needs.
O BMI does not take into account factors such as muscle mass or visceral fat — both consistently shown to have a significant impact on the development of chronic diseases and even longevity.
According to , the commission was made up of a group of 58 experts from various medical specialties and countries, including professionals “with lived experience” to include multiple perspectives.
Its objective was to establish unbiased criteria for diagnosing diseasestherapeutic interventions and public health strategies for obese individuals.
As a result, they suggest that BMI does a poor job of diagnosing clinical obesity. The team defines clinical obesity as a chronic, systemic disease in which excess body fat causes changes or damage to tissues, organs or the entire body.
The team reports that cases of clinical obesity can result in “serious end organ injuriescausing life-altering and potentially fatal complications”—for example, heart attack, stroke, and kidney failure.
However, the “preclinical obesity” represents a state of excess body fat with “preserved function of other tissues and organs and a variable but generally increased risk of developing clinical obesity and various other noncommunicable diseases,” such as certain types of cancer, heart disease, diabetes type 2, etc.).
Rather than relying on BMI to help assess overall health risk, the team suggests a set of other measures. “O excess adiposity must be confirmed, either by direct measurement of body fatwhen available, or by at least one anthropometric criterion (for example, waist circumference, waist-to-hip ratio or waist-to-height ratio (in addition to BMI, using validated methods and cut-off points appropriate to age, sex and ethnicity ”.
NPR adds that a DEXA scan has also been included among the methods that researchers suggest can effectively determine obesity, when finances and availability allow.
The research team highlights that only in cases of very high BMI is that we can reasonably assume dangerous levels of excess body fat without additional metrics to confirm.
Otherwise, the Individuals should speak with their doctors on the use of alternative means of assessment and developing an individualized care plan.
Teresa Oliveira Campos, ZAP //
