# Study of 844,108 adults: preclinical obesity rarely progressed to clinical over 10 years

- Published: 2026-11-12 06:22 UTC
- Section: Life & Health › Medicine
- Tags: clinical obesity, preclinical obesity, Lancet Commission obesity framework, BMI limitations, waist-to-height ratio, waist circumference, all-cause mortality, UK Biobank, All of Us, obesity progression
- URL: https://realtech.media/news/rt-3fdc5d35ccd559d9cbf06ff5_study_of_844/

**In four cohorts from China, the UK, the USA and Spain, clinical obesity carried a hazard ratio of 1.69 for all-cause death, preclinical obesity 1.19.**

![Study of 844,108 adults: preclinical obesity rarely progressed to clinical over 10 years](https://realtech.media/media/2026/11/d2fcc4b27bcdf25d.png)
*nature.com*

A study published on nature.com tested the 2025 Lancet Commission framework for diagnosing obesity on data from 844,108 adults in four cohorts: the Kailuan Study in China (137,795), the UK Biobank (436,203), All of Us in the USA (218,841) and the SIDIAP database in Spain (51,269). The authors compared it with classification by body mass index (BMI) alone, using prevalence, incidence and mortality data [1].

The framework separates clinical obesity, where excess adiposity is accompanied by organ dysfunction, from preclinical obesity, where adiposity is increased but function is preserved. It also recommends adding waist circumference and waist-to-height ratio to BMI [1].

## Reclassification by waist measures

BMI alone overestimated obesity in 1.2–3.1% of participants and underestimated it in 5.2–8.6%, depending on the cohort [1]. With the combined anthropometric definition, overall obesity prevalence rose from 17.8% to 21.3% in the Kailuan Study, from 24.0% to 27.3% in the UK Biobank, from 42.5% to 48.1% in All of Us and from 18.7% to 26.1% in SIDIAP. Across cohorts the increase was 3.3–7.4% relative to BMI-based classification [1].

Clinical obesity made up 22.7–31.3% of all obesity, which corresponds to a population prevalence of 5.6–10.9% [1].

## Progression and mortality

Over 10 years, 77.4–91.3% of people with preclinical obesity at baseline did not progress to clinical obesity [1].

Increased mortality risk was associated with obesity under the combined anthropometric definition, but not with obesity defined by BMI only [1]. Clinical obesity was associated with substantially higher all-cause mortality (hazard ratio 1.69, 95% confidence interval 1.64–1.73). Preclinical obesity carried a modest risk (hazard ratio 1.19, 95% confidence interval 1.14–1.24) [1].

The authors state that the findings support global adoption of the Lancet Commission diagnostic framework [1]. This is an observational analysis of cohort data; the results describe associations and do not establish treatment effects.

## Sources

1. [nature.com](https://www.nature.com/articles/s41586-026-11237-5)
2. [Наука.ua](https://nauka.ua/news/doklinichne-ozhirinnya-ne-perejshlo-u-klinichne-u-bilshosti-vipadkiv-ale-takozh-pidvishchilo-rizik-smerti)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-3fdc5d35ccd559d9cbf06ff5_study_of_844/