Experts Debate Proposed Changes to Obesity Diagnosis

Endocrine Society raises concerns over Lancet Commission's new obesity framework

Apr. 7, 2026 at 12:33pm

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A ghostly, translucent X-ray photograph showing the internal structures of a human torso with excess visceral fat, conceptually illustrating the nuanced biological factors involved in obesity.An X-ray image reveals the hidden complexities of obesity, as medical experts debate new diagnostic frameworks.Ann Arbor Today

The Endocrine Society has issued a response outlining its concerns with a proposed new framework for diagnosing obesity from The Lancet Commission. The Commission's plan to classify obesity as 'preclinical' or 'clinical' based on evidence of organ dysfunction has drawn criticism, with the Endocrine Society arguing it could delay needed care. The Commission's lead author defends the framework, saying it aims to provide a more rigorous disease definition for obesity.

Why it matters

The debate highlights ongoing challenges in accurately defining and diagnosing obesity, which affects over 40% of American adults. How obesity is classified can have major implications for patient access to treatment and the development of public health policies.

The details

The Lancet Commission's 2025 proposal calls for classifying obesity as either 'preclinical' or 'clinical' based on evidence of organ dysfunction caused by excess body fat. However, the Endocrine Society argues this criteria could create barriers to care, as patients often have multiple risk factors making it difficult to definitively attribute organ issues to obesity alone. The Endocrine Society also takes issue with the Commission's omission of type 2 diabetes from the list of obesity-induced organ dysfunctions.

  • The Lancet Commission's obesity framework was published in 2025.
  • The Endocrine Society's response was published in April 2026.

The players

Amy Rothberg

A physician at the University of Michigan who called for simpler ways to identify obesity earlier that don't rely on rigid diagnostic thresholds.

Ranganath Muniyappa

The first author of the Endocrine Society's response and a senior clinician at the National Institutes of Health.

Francesco Rubino

The first author of the Lancet Commission's obesity framework and chair of Metabolic and Bariatric Surgery at King's College London.

Endocrine Society

A medical organization that issued a guideline communication outlining its concerns with the Lancet Commission's proposed obesity framework.

Lancet Commission

The group that published a proposal in 2025 for a new framework to diagnose obesity as either 'preclinical' or 'clinical'.

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What they’re saying

“We need simpler ways to identify obesity earlier that don't involve rigid diagnostic thresholds.”

— Amy Rothberg, Physician, University of Michigan

“In routine practice, patients often have multiple interacting risk factors, making this determination difficult and potentially inconsistent across clinicians and settings.”

— Ranganath Muniyappa, Senior Clinician, National Institutes of Health

“The paper serves as a comprehensive catalogue of the very conceptual confusions that stem from the gap the Commission set out to resolve.”

— Francesco Rubino

What’s next

The Endocrine Society says it will continue to advocate for 'harmonization' between the Lancet Commission's framework and existing obesity staging systems that focus more on severity, complications and overall risk rather than strict causal attribution.

The takeaway

This debate highlights the ongoing challenges in accurately defining and diagnosing obesity, an issue that has major implications for patient access to treatment and the development of public health policies. While the Lancet Commission aims to provide a more rigorous disease definition, critics argue its framework could create new barriers to care.