Study analysis · The lancet. Diabetes & endocrinology · 2026

New data from 55 million adults reveals England's obesity crisis is worsening—and the sharpest rises are in young adults and the most deprived groups.

In England, about 30 in 100 adults had obesity by 2025, up from 26 in 100 in 2019, with new cases rising fastest in people in their 20s and 30s and in poorer and some ethnic minority groups.

Reading level
Low certainty
Level 2b · Individual cohort studyAssociation, not causationNo causal claims

Overview

What the study found

The study in plain English — the bottom line, every takeaway we extracted, and what to do with them.

In simple terms

This study looked at health records for almost everyone in England to see how common obesity was and how it changed over time. Because it just observed people without changing anything, it can show us patterns and links—like obesity being more common in some groups—but it can't prove what causes obesity. Think of it like watching traffic: you can see which roads are busy, but you can't prove why people chose those roads.

What’s the bottom line?

Researchers looked at health records for nearly 55 million adults in England from 2019 to 2025 to see how many people were newly recorded as obese and how many had obesity overall. They found that obesity is common and rising slightly, with bigger increases in younger adults and much higher rates in poorer groups and some ethnic groups.

How strong is this study?

The study is huge—it includes over 54 million adults—and uses official health records, which makes its numbers about obesity trends pretty reliable for England. However, because it's based on records and we only have the summary, we can't check for all possible mistakes or missing information, so we should be careful about trusting every detail. It's like having a very large photo of a crowd: you can count people, but you might miss some who are hidden.

Reporting

0 / 100

  • COI disclosureconflicts of interest not disclosed
  • Data availabilitydata not shared
  • Code availabilitycode not shared
Methodology

38 / 100

  • Randomizationnot randomized
  • Blindingblinding unclear
  • Control groupno control group
  • Sample size (n=54892390)+20/20
  • Follow-up+10/10
Publication

100 / 100

Statistical

54 / 100

  • P-valuesno p-values reported
  • Effect size+20/20
  • Confidence intervals+15/15
  • Pre-registrationnot pre-registered

Each component is scored out of 100 and then capped by the study design — a case series cannot reach the ceiling a randomised trial can, however well it is reported.

Where it sits

RCT reviews

Max 100

Randomized Trials

Max 90

Reviews of Cohort Studies

Max 85

Cohort Studies

Max 72

Reviews of Case-Control Studies

Max 63

Case-Control Studies

Max 58

Cross-Sectional & Case Series

Max 50

Expert Opinion

Max 5
StrongerWeaker
Cohort Studies
Level 2b
47

47 / 100

Probability of being correct

Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.

This design cannot establish causation — the findings describe an association, not a cause. Observational cohort design without randomization; cannot control for unmeasured confounding; temporal associations may be influenced by reverse causation or secular trends; no experimental manipulation; findings show associations and trends, not cause-effect.

No Conflicts

No conflicts of interest identified

Not Disclosed

No conflicts of interest identified. Study funded by non-commercial research organizations with no industry involvement.

Funder Involved
Undisclosed — Suspicious

Funders

Wellcome Trust
Health Data Research UK
British Heart Foundation Data Science Centre

No author list or competing interests section provided. Funding from non-commercial sources; no industry ties evident. The study uses national electronic health records, but independent analysis safeguards are not described.

Key takeaways

  1. 01

    About 22 out of every 1,000 adults were newly recorded as obese each year.

  2. 02

    The rate was 4% higher relatively by the end of the study compared with the start (IRR 1.04), which is about 1 extra new case per 1,000 adults per year.

  3. 03

    Overall, 30.3% of adults had obesity by 2025, up from 26.3% in 2019—an absolute increase of 4.0 percentage points.

  4. 04

    The poorest group had a 35% higher relative incidence than the least poor group (IRR 1.35); the absolute extra number of cases was not reported.

  5. 05

    The relative increase was 16% in adults aged 20-29 and 19% in those aged 30-39.

  6. 06

    For every 1,000 adults, about 22 were newly recorded with obesity each year, and the 4% relative rise means about 1 extra new case per 1,000 adults per year by the end.

  7. 07

    Overall, about 30 in 100 adults had obesity by 2025, compared with about 26 in 100 in 2019—a 4 percentage point absolute increase.

  8. 08

    The poorest groups had a 35% higher relative incidence, but the study did not report the absolute extra number of cases for that disparity.

  9. 09

    The data show clear inequalities but cannot prove what caused them.

Surprising findings

  • Geographical disparities were striking, with obesity prevalence varying nearly 6-fold across areas (8.5% to 48.1%).The abstract explicitly calls these disparities 'striking,' suggesting they exceeded typical expectations for regional variation.

Practical takeaways

Public health efforts should target young adults (20–39) and the most deprived groups, including Asian women, to address widening inequalities.

Based on abstract only; observational cohort cannot prove causation. Absolute excess cases for disparities not reported. Full methodology not verifiable.

low confidence

Use the 30.3% prevalence figure to communicate that nearly 1 in 3 adults in England has obesity, but avoid claiming causes.

Prevalence is based on BMI ≥30 or clinician diagnosis in EHR; first-recorded obesity may reflect new diagnosis/recording, not new biological onset.

low confidence

When interpreting trends, distinguish relative from absolute changes: the 4% rise is relative and equals about 1 extra case per 1000 person-years.

Absolute numbers for many subgroup disparities were not reported.

low confidence

Why this study matters

A whole-population snapshot: 55 million adults

The study analysed anonymised electronic health records for 54,892,390 adults in England from Nov 2019 to Apr 2025. During that time, 4,131,555 people had a first presentation of obesity; 55.1% were women, 75.2% White, 11.7% Asian, and 7.1% Black.

This is not a sample—it's essentially every adult in England, giving an unprecedented view of obesity trends.

Overall rise is small but significant—and prevalence is already high

First-recorded obesity incidence was 22 per 1000 person-years and rose 4% relatively by 2024-25 vs 2019-20 (IRR 1.04, 95% CI 1.01–1.07), about 1 extra case per 1000 person-years. Prevalence rose from 26.3% to 30.3%—an absolute increase of 4.0 percentage points.

It shows obesity is common and slowly rising, not exploding, but the absolute burden is large.

Young adults are driving the relative increase

The steepest relative increases in first-recorded obesity were in ages 20–29 (IRR 1.16, 95% CI 1.08–1.25) and 30–39 (IRR 1.19, 95% CI 1.13–1.25). These are relative increases of 16% and 19%, not absolute case numbers.

Obesity is often framed as an older-adult issue, but the fastest relative growth is in people of childbearing age.

Inequalities are stark and widening

Incidence was 35% higher relatively in the most deprived vs least deprived quintile (IRR 1.35, 95% CI 1.28–1.42). Disparities were larger in women (IRR 1.54) and particularly Asian women (IRR 1.94, 95% CI 1.86–2.02). Absolute excess cases were not reported.

It highlights that obesity is not evenly distributed—socioeconomic and ethnic inequalities are central.

Where you live matters—a lot

Geographical prevalence varied from 8.5% to 48.1%, nearly a 6-fold difference. The lowest group was least deprived White men aged 18–19 (4.3%); the highest was most deprived Black women aged 60–69 (66.1%).

Your postcode and demographics are strongly linked to obesity prevalence.

Prevention and intergenerational risk

The authors conclude obesity is 'preventable' and that rising rates in childbearing-age adults risk 'perpetuating intergenerational cycles of health inequality.'

It frames obesity as a solvable public health issue with long-term consequences.

Want the whole report?

Detailed mode opens the full scientific breakdown — every score component, the methodology, conflicts of interest, the evidence analysis behind each claim, and the raw study data.

Standing

The people behind it

The researchers who wrote the study this analysis is built on.

Authored by

17 researchers

If this is your work, this is how we attribute it on Fit Body Science. Robert A. Fletcher is listed as the lead author.