TOPLINE:

Applying The Lancet Diabetes and Endocrinology Commission’s new definition of obesity, a large UK Biobank analysis reported that both preclinical and clinical obesity are common, with the latter increasing risks for incident stroke, heart failure, and myocardial infarction.

METHODOLOGY:

• To address the limitations of traditional BMI-based definitions of obesity, The Lancet Diabetes and Endocrinology Commission introduced a revised definition in 2025 that emphasizes functional consequences rather than BMI thresholds.
• Researchers conducted a retrospective cohort analysis of 502,233 adults in the UK Biobank to evaluate the epidemiology of preclinical and clinical obesity and their associations with incident cardiovascular disease.
• They applied the new obesity definition of elevated body fat percentage, a BMI ≥ 40, or at least two anthropometric indicators of excess adiposity; cases were classified as preclinical (no functional deficits) or clinical (physical impairment or obesity-related organ dysfunction).
• At baseline, participants completed detailed surveys on sociodemographic characteristics, health behaviors, and medical history and underwent physical measurements, imaging, and blood collection for genetic and biomarker analyses.
• Progression from preclinical to clinical obesity was evaluated over 12 years.

TAKEAWAY:

• The prevalence of preclinical and clinical obesity was 31.2% and 36.6%, respectively; approximately 40% of participants previously categorized as overweight under World Health Organization criteria were reclassified as having clinical obesity.
• Clinical obesity was more prevalent than preclinical obesity among men, older adults, South Asian individuals, and those with lower education or income levels.
• Overall, 24.1% of individuals progressed from preclinical to clinical obesity during follow-up.
• Among individuals without baseline cardiovascular disease, clinical obesity was associated with increased risks for incident stroke (hazard ratio [HR], 1.51), heart failure (HR, 2.16), and myocardial infarction (HR, 1.82).

IN PRACTICE:

“This observation highlights the importance of performing a comprehensive history, examination, and studies to diagnose obesity complications, which are often underreported by patients and underrecognized by clinicians,” the authors of the study wrote.

SOURCE:

The study was led by Sohail Zahid, Ciccarone Center for the Prevention of Cardiovascular Disease, Johns Hopkins University School of Medicine, Baltimore. It was published online in Obesity.

LIMITATIONS:

Reliance on electronic health records and diagnostic codes introduced the potential for data mischaracterization. Not accounting for time-varying exposures, surveillance frequency, and competing risks such as death likely underestimated transitions to clinical obesity. The UK Biobank population lacked ethnic and socioeconomic diversity, and the dataset does not include adjudicated outcomes or regularized follow-up.

DISCLOSURES:

One author reported receiving consulting fees and research grants and serving on an endpoint review committee for pharmaceutical companies. Another author reported being a cofounder, equity holder, and stock owner in pharmaceutical companies.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.