Elsevier

The Lancet

Volume 377, Issue 9765, 12–18 February 2011, Pages 557-567
The Lancet

Articles
National, regional, and global trends in body-mass index since 1980: systematic analysis of health examination surveys and epidemiological studies with 960 country-years and 9·1 million participants

https://doi.org/10.1016/S0140-6736(10)62037-5Get rights and content

Summary

Background

Excess bodyweight is a major public health concern. However, few worldwide comparative analyses of long-term trends of body-mass index (BMI) have been done, and none have used recent national health examination surveys. We estimated worldwide trends in population mean BMI.

Methods

We estimated trends and their uncertainties of mean BMI for adults 20 years and older in 199 countries and territories. We obtained data from published and unpublished health examination surveys and epidemiological studies (960 country-years and 9·1 million participants). For each sex, we used a Bayesian hierarchical model to estimate mean BMI by age, country, and year, accounting for whether a study was nationally representative.

Findings

Between 1980 and 2008, mean BMI worldwide increased by 0·4 kg/m2 per decade (95% uncertainty interval 0·2–0·6, posterior probability of being a true increase >0·999) for men and 0·5 kg/m2 per decade (0·3–0·7, posterior probability >0·999) for women. National BMI change for women ranged from non-significant decreases in 19 countries to increases of more than 2·0 kg/m2 per decade (posterior probabilities >0·99) in nine countries in Oceania. Male BMI increased in all but eight countries, by more than 2 kg/m2 per decade in Nauru and Cook Islands (posterior probabilities >0·999). Male and female BMIs in 2008 were highest in some Oceania countries, reaching 33·9 kg/m2 (32·8–35·0) for men and 35·0 kg/m2 (33·6–36·3) for women in Nauru. Female BMI was lowest in Bangladesh (20·5 kg/m2, 19·8–21·3) and male BMI in Democratic Republic of the Congo 19·9 kg/m2 (18·2–21·5), with BMI less than 21·5 kg/m2 for both sexes in a few countries in sub-Saharan Africa, and east, south, and southeast Asia. The USA had the highest BMI of high-income countries. In 2008, an estimated 1·46 billion adults (1·41–1·51 billion) worldwide had BMI of 25 kg/m2 or greater, of these 205 million men (193–217 million) and 297 million women (280–315 million) were obese.

Interpretation

Globally, mean BMI has increased since 1980. The trends since 1980, and mean population BMI in 2008, varied substantially between nations. Interventions and policies that can curb or reverse the increase, and mitigate the health effects of high BMI by targeting its metabolic mediators, are needed in most countries.

Funding

Bill & Melinda Gates Foundation and WHO.

Introduction

Excess bodyweight is an important risk factor for mortality and morbidity from cardiovascular diseases, diabetes, cancers, and musculoskeletal disorders, causing nearly 3 million deaths every year worldwide.1, 2, 3, 4 National, subnational, and multicentre studies have shown that adiposity, as measured by body-mass index (BMI), has increased in recent decades in many populations,5, 6, 7, 8, 9, 10, 11, 12 although BMI seems to have been stable or even decreased in some groups.6, 7, 9, 13

Some have argued that increasing BMI is a pandemic14, 15 that could reverse life-expectancy gains in high-income nations.16 Therefore, there is substantial interest in curbing or reversing rising BMI trends. Reliable information about these trends is needed to assess the implications of rising BMI on population health, set policy priorities, and evaluate their success. Several studies used national health surveys, multicentre studies, or reviews of published studies to estimate adult BMI levels or trends worldwide and in specific regions, or did cross-country comparative analyses.6, 17, 18, 19, 20, 21 Some of these studies used BMI data based on both measured and self-reported weight and height,19 even though self-reported measures are biased.22 Others focused exclusively on women20 or selected countries,6, 19, 20, 21 relied mainly on community studies,6, 17 or combined community and national studies without distinguishing them.18 Many recent high-quality national health examination surveys have measured BMI, providing an opportunity to systematically and comprehensively assess regional and national trends.

We reviewed and accessed published and unpublished studies to collate comprehensive BMI data. We developed and applied statistical methods to systematically address measurement comparability, missing data, non-linear trends and age patterns, and national versus subnational and community representativeness. With these data and methods, we estimated BMI trends and their uncertainties by country between 1980 and 2008.

Section snippets

Study design

We estimated 1980–2008 trends in mean BMI and their uncertainties, by sex, for 199 countries and territories in the 21 subregions of the Global Burden of Diseases, Injuries, and Risk Factors study, which are grouped into seven merged regions (webappendix p 19). 1980 was selected as the beginning of the analysis period because few data were available earlier. Evidence suggests that central adiposity measures—eg, waist circumference—might best predict disease risk at the individual level;23 other

Results

Our analysis included 960 country-years of data, with 9·1 million participants (figure 1). 361 country-years were from 29 high-income countries and 599 covered 140 additional countries. Japan had the most national data with 16 national data sources since 1980, followed by China with eight national sources and 64 subnational or community sources. There were 30 countries for which we could not identify any data. The Caribbean had the most countries with no usable data (seven of 20).

There were

Discussion

Between 1980 and 2008, age-standardised mean global BMI increased by 0·4–0·5 kg/m2 per decade in men and women. We noted substantial differences across regions and sexes. Notably, the subregion trends spanned a 1·4 kg/m2 range per decade for men and 1·9 kg/m2 per decade for women, with BMI rise largest in Oceania in both sexes. The regions with almost flat trends or even potential decreases were central and eastern Europe for women, and central Africa and south Asia for men. An implication of

References (49)

  • N Yoshiike et al.

    Twenty-year changes in the prevalence of overweight in Japanese adults: the National Nutrition Survey 1976–95

    Obes Rev

    (2002)
  • DM Kim et al.

    Prevalence of obesity in Korea

    Obes Rev

    (2005)
  • KL Rennie et al.

    Prevalence of obesity in Great Britain

    Obes Rev

    (2005)
  • H Wang et al.

    Trends in the distribution of body mass index among Chinese adults, aged 20–45 years (1989–2000)

    Int J Obes (Lond)

    (2007)
  • S Houterman et al.

    Trends in total and high density lipoprotein cholesterol and their determinants in The Netherlands between 1993 and 1997

    Int J Epidemiol

    (2001)
  • J Roth et al.

    The obesity pandemic: where have we been and where are we going?

    Obes Res

    (2004)
  • AM Prentice

    The emerging epidemic of obesity in developing countries

    Int J Epidemiol

    (2006)
  • SJ Olshansky et al.

    A potential decline in life expectancy in the United States in the 21st century

    N Engl J Med

    (2005)
  • DL Pelletier et al.

    Trends in body mass index in developing countries

    Food Nutr Bull

    (1998)
  • WPT James et al.

    Overweight and obesity (high body mass index)

  • F Sassi et al.

    The obesity epidemic: analysis of past and projected future trends in selected OECD countries

    (2009)
  • BM Popkin et al.

    Is there a lag globally in overweight trends for children compared with adults?

    Obesity (Silver Spring)

    (2006)
  • SC Gorber et al.

    A comparison of direct vs. self-report measures for assessing height, weight and body mass index: a systematic review

    Obes Rev

    (2007)
  • HJ Schneider et al.

    The predictive value of different measures of obesity for incident cardiovascular events and mortality

    J Clin Endocrinol Metab

    (2010)
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