OW2025: A Passionate Debate of the Lancet Commission Report
On the opening day of ObesityWeek yesterday, we got quite a treat in a passionate debate of the Lancet Commission report on clinical obesity. Four of our favorite people – Sue Yanovski, Bob Kushner, Fatima Cody Stanford, and Donna Ryan – participated and made it memorable. We walked away with a clear understanding that many obesity researchers and clinicians are not ready to embrace this report.
Yanovsky chaired. Kushner presented an overview. Stanford presented the merits of the report. Ryan offered a critique of its shortcomings.
Two Simple Objectives
Kushner was both thorough and matter-of-fact in laying out an overview of the commission’s work. He explained that the objectives were simple: to better define excess adiposity and health in the context of obesity. The World Health Organization had a pretty good definition for obesity years ago when they defined it as excess adiposity that harms health. The devilish details come with trying to define “excess” and the health harms.
Getting Beyond BMI
Stanford made it clear that she likes the report because it takes us beyond BMI for defining obesity. She pointed out a number of fundamental problems with BMI, starting with the fact that it was never intended to be a measure of health. Perhaps most boldly, she said that because it was designed as a measure for white European males, it promotes implicit racism in our thinking about obesity. “Racism is still pervasive in obesity because of BMI,” she told us.
BMI is simply an unreliable indicator of adipose tissue distribution in different racial and ethnic populations at a given BMI value.
A Missed Opportunity
Ryan made a compelling case for disappointment with the Lancet Commission Report. At the essence of her argument is a contention that the reports adds confusion to the diagnosis of obesity. And it simply makes no sense that a person with excess adiposity and type 2 diabetes can be classified as having “preclinical” obesity if that is the only condition they have in addition to excess adiposity. Likewise, she said, neither MASLD without fibrosis nor atherosclerotic heart disease would, by themselves, identify someone as having clinical obesity.
Further, she pointed out that the definition of clinical obesity is so narrow that only 9.7% of the adult U.S. population meets the criteria. These numbers come from a recent recent analysis by Yun Shen and Gang Hu.
“There is nothing more expensive than a missed opportunity,” said Ryan in a closing rebuttal. By looking back with a restrictive definition of clinical obesity, she contends that the Lancet Commission missed an opportunity. We should instead, look forward and seize the opportunity to treat obesity and prevent a whole host of chronic diseases – not wait for those diseases to develop and become resistant or refractory to treatment.
So she called for reshaping the recommendations of the commission to look forward to better care for people living with obesity and better prevention of its complications. This an opportunity. Carpe diem!
Click here for Kushner’s overview, here for Stanford’s presentation, here for Ryan’s presentation, and here for Ryan‘s rebuttal. Come back later if you want her primary presentation, which we will post here as soon as we have it.
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November 5, 2025
November 05, 2025 at 6:51 pm, Dr Cal Paterson said:
The Lancet Commission has contributed usefully to the debate about how to identify obesity and plan for its management, particularly at the population level. Its findings left some important omissions, not least of which was the sidestepping of mental and psychosocial aspects of obesity illness, both diagnostically and aetiologically. However a frequent and persisting misunderstanding about the commission’s findings seems to be that they were ‘defining’ obesity or its diagnosis. My understanding was that they were collating knowledge and establishing consensus regarding what is happening, pathologically, in a patient with, or at risk of, obesity or related illness, as a step towards, one day, in the future, a definition of obesity as an illness (in the ICD, for example). People seem to be reacting to the commission’s findings as if it has tried to have ‘the last word’ on what obesity is; But if one actually reads the the commission’s work, it did not seek to do this, nor has it done this, at any point. Let the discussion about obesity as an illness, ‘pre-clinical’ or ‘clinical’ or otherwise, rage on – for that, I think, was the aim of the commission; to inform discussion and planning, rather than to foreclose it.
November 05, 2025 at 7:11 pm, Valerie M. O'Hara said:
100% spoty on Dr Ryan! Waiting until end staged diseases that we know often are obesity-driven would mean worse outcomes for many – particularly our children particularly in an era of more effective treatment options. We must do better and move forward!