The weight of the world - Trends in adult BMI (1975-2014) - pooled analysis

Q: What was the study’s main aim regarding BMI trends?

To estimate trends in mean adult BMI and in the prevalence of multiple BMI categories across all countries.

Q: How were BMI trends estimated in the study?

Population-based studies with measured height and weight were reanalysed using a consistent protocol and a Bayesian hierarchical model to estimate trends from 1975 to 2014.

Q: Did the study find that the global obesity target for 2025 is achievable?

The probability of meeting the global obesity target is virtually zero if post-2000 trends continue.

Sep 8, 2026

Upload by Lucas Vance

Global trends in adult body-mass index (BMI) describe changes in population BMI distribution and the share of people facing underweight and severe obesity risks. This study reanalysed population-based measurements of adults (18+ years) across 200 countries from 1975 to 2014 using a Bayesian hierarchical model. It estimated mean BMI and BMI-category prevalences by sex, and assessed whether obesity rise can be halted by 2025 under continued post-2000 trends.

LanguageEnglish

CategoryPaper Templates

FormatDOCX

Pages54

Reading Time19 min

AccessFree to download

Summary

Background

Methods

Findings

Interpretation

Funding

Introduction

The weight of the world – trends in adult body mass index in 200 countries since 1975: pooled analysis of 1,698 population-based measurement studies with 19.2 million participants NCD Risk Factor Collaboration (NCD-RisC) Summary Background: Trends in mean body mass index (BMI) characterise shifts in the population distribution of BMI, and prevalences of underweight, and severe and morbid obesity (BMI ≥ 35 and 40 kg/m2, respectively) show what proportion of the population are at high risks of adverse health outcomes. Our aim was to estimate trends in mean BMI and in prevalences of various BMI categories for adults in all countries. Methods: We reanalysed population-based studies with measured height and weight data in adults aged 18 years and older using a consistent protocol. We applied a Bayesian hierarchical model to these data to estimate trends from 1975 to 2014 in mean BMI and in the prevalences of BMI < 18.5 kg/m2 (underweight), 18.5 to <20 kg/m2, 20 to <25 kg/m2, 25 to <30 kg/m2, 30 to <35 kg/m2, 35 to <40 kg/m2, ≥40 kg/m2 by sex in 200 countries and territories, organised in 21 regions. We calculated the posterior probability of meeting the target of halting by 2025 the rise in obesity compared to its 2010 levels, if post-2000 trends continue. Findings: Global age-standardised mean BMI increased from 21.7 kg/m2 (95% credible interval 21.3-22.1) in 1975 to 24.2 kg/m2 (24.0-24.4) in 2014 in men, and from 22.1 (21.7-22.5) kg/m2 in 1975 to 24.4 (24.2-24.6) kg/m2 in 2014 in women. Regional mean BMIs in 2014 for men ranged from 21.4 kg/m2 in Central Africa and South Asia to 29.2 (28.6-29.8) kg/m2 in Polynesia and Micronesia; for women the range was from 21.8 (21.4-22.3) kg/m2 in South Asia to 32.2 (31.5-32.8) kg/m2 in Polynesia and Micronesia. Over these four decades, global prevalence of underweight (BMI <18.5 kg/m2) declined from 13.8% (10.5-17.4) to 8.8% (7.4-10.3) in men and from 14.6% (11.6-17.9) to 9.7% (8.3-11.1) in women. South Asia had the highest prevalence of underweight in 2014, 23.4% (17.8-29.2) in men and 24.0% (18.9-29.3) in women. Prevalence of obesity increased from 3.2% (2.4-4.1) in 1975 to 10.8% (9.7-12.0) in 2014 in men, and from 6.4% (5.1-7.8) to 14.9% (13.6-16.1) in women. 2.3% (2.0-2.7) of the world’s adult men and 5.0% (4.4-5.6) of adult women are severely obese. Morbid obesity is 0.64% (0.46-0.86) among men and 1.6% (1.3-1.9) among women. If post-2000 trends continue, the probability of meeting the global obesity target is virtually zero. Rather, if these trends continue, by 2025, global obesity prevalence will surpass 17% in men and 21% in women; severe obesity will surpass 6% in men and 9% in women. Interpretation: If current trends continue, the world will not meet the global obesity target, and will face an epidemic of severe obesity. Underweight nonetheless remains prevalent in the world’s poorest regions, especially in South Asia. Funding: Wellcome Trust; Grand Challenges Canada Introduction High body mass index (BMI) is an important risk factor for cardiovascular and kidney diseases, diabetes, some cancers and musculoskeletal conditions. HYPERLINK \l "_ENREF_1" \o "Singh, 2013 #11" ADDIN EN.CITE ADDIN EN.CITE.DATA 1-7 Concerns about the health and economic burden of increasing BMI have led to adiposity being included among the global non-communicable diseases (NCD) targets, with a target of halting, by 2025, the rise in the prevalence of obesity compared to 2010 (i.e., age-standardised prevalence in 2025 is no more than its 2010 level). ADDIN EN.CITE ADDIN EN.CITE.DATA HYPERLINK \l "_ENREF_8" \o "World Health Organization, 2013 #37" 8, HYPERLINK \l "_ENREF_9" \o "Kontis, 2014 #38" 9 HYPERLINK \l "_ENREF_10" \o "Kontis, 2014 #38" Information on HYPERLINK \l "_ENREF_18" \o "Mendez, 2005 #136" whether countries are on track to achieve this target is needed to support accountability towards the global NCD commitments. HYPERLINK \l "_ENREF_10" \o "Beaglehole, 20

FAQs

What was the study’s main aim regarding BMI trends?

To estimate trends in mean adult BMI and in the prevalence of multiple BMI categories across all countries.

How were BMI trends estimated in the study?

Population-based studies with measured height and weight were reanalysed using a consistent protocol and a Bayesian hierarchical model to estimate trends from 1975 to 2014.

Did the study find that the global obesity target for 2025 is achievable?

The probability of meeting the global obesity target is virtually zero if post-2000 trends continue.

Sep 8, 2026

Upload by Lucas Vance