Study Reveals Hidden Obesity Among Those with Normal BMI

Recent research has uncovered a concerning health trend: many individuals classified as having a “normal” body mass index (BMI) may actually be living with obesity. This finding highlights that relying solely on BMI could mask significant health risks. An international team of scientists analyzed survey data from the World Health Organization (WHO) and determined that approximately one in five people worldwide with a healthy BMI exhibit signs of abdominal obesity.

The study, published in JAMA Network Open this month, emphasizes that these individuals, often referred to as “skinny-fat,” are at a higher risk for health issues such as high blood pressure and diabetes. The researchers assert that focusing exclusively on BMI may lead medical professionals to overlook critical health concerns. They noted, “Relying solely on BMI may be insufficient to identify these high-risk individuals and provide timely interventions.”

Reevaluating Definitions of Obesity

Traditionally, obesity is defined as having a BMI of 30 or greater. Yet, recent advocacy from medical professionals has called for a broader understanding of obesity. In January, a coalition of experts, supported by organizations like the American Heart Association, proposed alternative criteria for diagnosing obesity. Their recommendations suggest that physicians should combine BMI with additional measurements of body fat, such as waist circumference, to gain a fuller picture of a patient’s health.

In their analysis, researchers scrutinized data from the WHO STEPS survey, a long-term initiative that tracks risk factors for noncommunicable diseases globally. The study encompassed nearly half a million participants across 91 countries from 2000 to 2020. The findings revealed that 21% of respondents classified as normal weight had abdominal obesity, characterized by a waistline large enough to qualify as obese. This group exhibited a higher prevalence of conditions like hypertension, high cholesterol, and diabetes compared to their normal-weight counterparts.

The Need for Comprehensive Health Assessments

The implications of this study resonate beyond just BMI. A separate investigation earlier this month indicated that nearly 70% of Americans fall under the updated obesity definition, with 25% of those possessing a normal BMI yet showing signs of excess body fat. The results suggest that individuals with “skinny obesity” face a greater overall risk of health complications than those classified as nonobese.

The researchers behind the recent study argue that their work is the first to explore the prevalence of hidden obesity on a global scale. They advocate for a dual approach to assessing obesity—utilizing both BMI and waist circumference to achieve a more accurate evaluation of cardiovascular and metabolic health. “Our findings suggest the need to use both BMI and waist circumference together, rather than in isolation, to provide a more complete and accurate assessment of cardiometabolic risk across diverse populations,” they stated.

As these findings emerge, individuals are encouraged to seek comprehensive checkups that extend beyond BMI measurements. This approach could help identify hidden health risks, leading to timely interventions and better overall health outcomes.