The Lancet’s Landmark Report on Obesity

What You Need to Know 

Big news in the world of obesity medicine: The Lancet Commission just released a groundbreaking report redefining obesity—not just as excess weight, but as a condition characterized by excess adiposity, with multifactorial causes and still incompletely understood. 

The commission—made up of 58 international experts, including individuals with lived experience of obesity—has laid out clear diagnostic criteria that will change how we assess, diagnose, and manage obesity in clinical practice. 

Key Takeaways 

1. Obesity is more than BMI.
   The commission makes it clear: BMI should NOT be used as an individual diagnostic tool but rather as a population-level screening measure. Instead, clinicians should confirm excess adiposity using direct body fat measurements or at least one validated anthropometric measure (e.g., waist circumference, waist-to-height ratio), adjusted for age, sex, and ethnicity.
2. A new classification system: Preclinical vs. Clinical Obesity.

• • Preclinical Obesity: Excess adiposity with preserved organ function but an increased risk of chronic diseases (type 2 diabetes, CVD, certain cancers, mental disorders). 
  • Clinical Obesity: A chronic, systemic disease where excess adiposity has started affecting tissue and organ function, potentially leading to severe complications (e.g., heart attack, stroke, renal failure).

3. Diagnosis must go beyond weight.

The new approach starts with BMI as a vital sign but incorporates:
✅ Blood biomarkers
✅ Metabolic health
✅ Functional capacity (Can the person carry out daily activities?)
✅ Organ system function (kidney, nervous, urinary, reproductive) 

Why This Matters 

This report marks a major shift from the outdated weight-centric view of obesity to a disease-based model—one that recognizes obesity as a complex, multifactorial condition rather than a simple matter of willpower. 

For clinicians, this means better tools for diagnosis, more personalized treatment strategies, and a stronger framework for advocating for obesity as a serious medical condition—not just a lifestyle issue. 

Want to dive deeper? Check out the full Lancet Commission report here. 

*In the Obesity Nutrition Course I'll be launching in a few months, I've dedicated an entire module to unpacking the findings from The Lancet with practical, real-world scenarios. You can get on the wait list here.

Interested in learning more about metrics beyond BMI? Listen to episode 31 here.