The Obesity Prevention Source

Half  a Billion and Counting: Obesity's Numbers Continue to Rise

Obesity has truly become a worldwide problem, affecting countries rich and poor. So just how many men, women, and children are overweight or obese? It’s a natural question—and a surprisingly hard one for researchers to answer. The problem’s vast. The data, from some regions, quite spotty. So projections from one group differ a bit from the estimates of another. But all point to tremendous increases in global obesity rates over the past three decades—and find that the epidemic shows no signs of abating without dedicated efforts to combat it. (1-5)

One of the most recent and careful global estimates finds that roughly 500 million adults are obese (defined as a body mass index, or BMI, of 30 or higher). (1)  That’s almost 10 percent of men and 14 percent of women—and it’s nearly double the rate of obesity in 1980. Nearly 1.5 billion adults were overweight or obese (defined as a BMI of 25 or higher). Data are scarcer on obesity in children, but one global estimate finds that in 2010, 43 million preschool children were overweight or obese, according to the latest international benchmarks set for children, and obesity rates have been steadily rising in preschoolers since the 1990s. (5)  If nothing is done to reverse the epidemic, more than 1 billion adults are projected to be obese by 2030. (2)

Not that long ago, obesity was largely a problem of the rich, primarily in wealthy countries. Globalization, though, has made the world wealthier. And as poor countries move up the income scale, and people shift from subsisting on traditional diets to overeating on Western diets, obesity becomes a disease of the poor. The result: Over the past few decades, obesity has quietly become a “pandemic” in developing countries. (4)

One paradox of this so-called “nutrition transition” is that even as obesity rates rise, underweight persists, sometimes within the same household. (6) Low- and middle-income countries often face a dual burden—the infectious diseases that accompany malnutrition and, increasingly, the debilitating chronic diseases linked to obesity and Western lifestyles.

This article gives a brief overview of global obesity trends in adults. Overweight refers to a BMI of 25 to 29.9, obesity, a BMI of 30 or higher. The combined category of “overweight and obese” refers to a BMI of 25 or higher. Since Asians have a higher risk of weight-related diseases at lower BMI levels, some countries in Asia do use lower thresholds for overweight and obesity. But for the purposes of this article, assume that a study has used the standard international adult BMI cut points of 25 for overweight and 30 for obesity, unless otherwise specified. A related article covers global obesity trends in children.

Quick links: North America | Central and South America | Europe and Central Asia | North Africa and Middle East | Sub-Saharan Africa | Asia-Pacific Region

North America

In 2010, 36 states had obesity rates of 25 percent or higher, and 12 of those had obesity rates of 30 percent or higher. See a figure that maps U.S. obesity trends over the past 20 years.

Read the media coverage of the latest U.S. obesity numbers, and you might think the country had turned the corner on the epidemic: "American Obesity Rates Have Hit Plateau, CDC Data Suggest,"(7) and "Good News: Obesity Rates Leveling Off." (8) But those optimistic headlines tell only part of the story. While U.S. obesity rates have, overall, stayed steady since 2003, they have more than doubled since 1980. They remain worrisomely high—the highest among all of the high-income countries in the world. (1) And obesity takes a heavier toll on some U.S. ethnic and racial groups than others, with rates continuing to rise. (9) A closer look at the U.S. numbers in adults:

• Roughly two out of three U.S. adults are overweight or obese (69 percent) and one out of three is obese (36 percent). (9)
• Obesity rates are higher in non-Hispanic black, Hispanic, and Mexican American adults than in non-Hispanic white adults. (9)
• Non-Hispanic black women have the highest rates of obesity in the U.S.—nearly 59 percent, compared to 44 percent in Mexican American women, 41 percent in Hispanic women, and 33 percent in non-Hispanic white women. (9)
• Though overall obesity rates in the U.S. have stayed steady since 2003, obesity rates have continued to climb in men, non-Hispanic black women, and Mexican American women. (9)  
• If U.S. trends continue unabated, by 2030, estimates predict that roughly half of all men and women will be obese. (10)

Obesity rates in Canada are not quite as high as they are in the U.S., but Canada has seen similarly dramatic increases over the past three decades. In 1979, 14 percent of Canadian adults were obese. By 2008, 25 percent of adults were obese, and 62 percent were overweight or obese. (11) Obesity is also more common among Canada's Aboriginal population than it is among other groups: Surveys from 2007–2008 find obesity rates of 25 percent among Aboriginal groups who live outside of reservations, compared with 17 percent in non-Aboriginal groups. (11)

Central and South America

There's a dearth of long-term data on obesity rates in Central and South America. Unlike the U.S., where multiple national surveys regularly assess BMI across all age groups, many Central and South American countries tend to field smaller surveys—say, of  BMI patterns in city dwellers, or within specific age groups—that may not give as accurate a picture of obesity trends overall. But taken together, these surveys show that Central and South America have seen steady BMI increases over the past three decades, as well as current obesity rates that rival those of the U.S. and Canada. (1) A closer look at data from the region:

• Among women, between 1980 and 2008, Finucane and colleagues estimate that the average BMI in Central Latin America and Southern Latin America increased by 1.3 and 1.4 units per decade. (1) Men in these regions have seen similar increases in obesity, though not quite as steep as those in women. (1)  
• In 2008, more than 30 percent of women in Central and Southern Latin America were obese, according to Finucane’s estimates, and about 25 percent of men in Southern Latin America and 20 percent of men in Central Latin America were obese. (1)
• In Mexico, a recent report, based on 2006 data collected across Mexico, finds that roughly 30 percent of Mexican adults are obese and 70 percent are overweight or obese, a 12 percent increase since 2000. (12) Three out of four Mexican adults have abdominal obesity, and women have higher rates of obesity and abdominal obesity than men.

There’s evidence that Mexico and other countries in Central and South America are already seeing the burden of obesity shift from the wealthy to the poor. In Mexico, for example, wealthier groups still have higher rates of obesity than lower socioeconomic groups. (12) But the differences in average BMI between Mexico’s more-developed regions in the north and less-developed areas in the south are small. (12)  In Brazil, meanwhile, from 1975 to 2003, obesity rates rose far more quickly among people with lower incomes than they did among the wealthiest Brazilians; by 2003, the difference in obesity rates between wealthy and lower-income men had narrowed, and the differences among women had nearly disappeared. (13)

Europe and Central Asia

The European obesity epidemic is far from uniform—a reflection, perhaps, of Europe’s diverse economic and cultural landscape. But it’s clear that obesity rates are rising across the continent, though they are not as high as they are in the U.S., and are not rising as rapidly as here. (1,14)

One challenge to tracking weight trends across Europe is that some countries, especially those of the former Soviet bloc, have only sparse data. But the best available estimates find that over the past 30 years, average BMI in men has been rising a bit more rapidly in Western and Central Europe than in Eastern Europe and Central Asia (0.6, 0.4, 0.2, and 0.2 units per decade, respectively). (1) Average BMI in women stayed relatively stable in Eastern and Central Europe and Central Asia—some of the very few places on the globe to report such a trend—and increased by 0.4 units per decade in Western Europe. (1) 

In 2008, men in Western and Central Europe had higher rates of obesity than men in Eastern Europe (20 to 25 percent, versus 15 to 20 percent). (1) In women, obesity rates were higher in Eastern Europe (25 to 30 percent) than in Western Europe (15 to 20 percent) or Central Europe (20 to 25 percent). (1) Not all researchers have found this pattern among Eastern European women, however; having more data from the region would help tease out these trends. (14)

Within Western Europe, there are marked differences in obesity rates from country to country. In 2008, for example, average BMI in the U.K. was among the highest in Western Europe—27.4 in men and 26.9 in women. France and Switzerland, meanwhile, had mean BMIs that were far lower—25.9 and 26.2 in men, and 24.8 and 24.1 in women, respectively. (1) The U.K.’s obesity rates have risen by about a percentage point per year since the mid-1990s, and in 2009, about 25 percent of U.K. adults were obese and 57 percent were overweight. (14)

North Africa and the Middle East

Data are scarce from many countries in North Africa and the Middle East, but even so, there’s compelling evidence that obesity rates are on the rise. (1,15) Researchers have taken a closer look at obesity trends in the six Arabian Gulf states (Oman, Bahrain, United Arab Emirates, Saudi Arabia, Qatar, and Kuwait), as these countries have seen tremendous increases in wealth—and weight—since the discovery of oil reserves in the 1960s. (16)

Today, obesity rates in some of the Arab Gulf countries rival or exceed those of the U.S.: In Saudi Arabia, for example, recent surveys have found that 28 percent of men and 44 percent of women are obese, and 66 percent of men and 71 percent of women are overweight or obese. In Kuwait, 36 percent of men and 48 percent of women are obese, while 74 percent of men and 77 percent of women are overweight or obese. (16) Though obesity rates are higher among women in the region than men, they appear to be rising more quickly in men than in women.

Sub-Saharan Africa

Under-nutrition has historically received more public health attention in sub-Saharan Africa than over-nutrition. Yet today, obesity and the chronic diseases that accompany it have become a growing problem across this huge and diverse continent. Some have called it a “silent epidemic,” (17) striking countries that are still struggling with the health and economic burdens of malnutrition, stunting, infectious disease, and high childhood mortality rates.

As in other developing regions, nationally representative studies of obesity in sub-Saharan Africa are scarce. The studies that are available, though, suggest that obesity rates vary widely from country to country.  

For example, in 2008, the average BMI among men in the Democratic Republic of the Congo was 19.9—the lowest in the world. (1) Yet in South Africa, men had an average BMI of 26.9—on par with the average BMIs in Canada (27.5) and the U.S. (28.5). (1) 

Some studies in urban settings have found that obesity rates are rising more quickly in the poor than in the rich. (18) More research is needed to give a fuller picture of obesity trends across the continent.

Asia-Pacific Region

Though Asia is home to some of the leanest populations on the globe, (1) there’s no question that obesity has become a serious and growing problem across the region over the past two decades. Obesity rates in “Australasia” (Australia and New Zealand) are not far behind those in the U.S. and Canada—about 25 percent for men and women. (1) In Oceania, the average BMI has climbed by 1.3 units per decade over the past three decades; 15 to 20 percent of men and 25 to 30 percent of women there are obese. (1)

Some countries in South Asia, Southeast Asia, and East Asia have mean BMIs that are among the lowest in the world. In Bangladesh, for example, the estimated mean BMI in 2008 was less than 21, for both men (20.4) and women (20.5). But even Bangladesh and other countries where under-nutrition remains a significant threat—Cambodia, China, India, Nepal, and Viet Nam—have seen the prevalence of overweight and obesity in women increase from the 1990s through the mid-2000s, by anywhere from 3.5 to 38.5 percent a year. (4)

Recent trends in China and India are of special concern. Although obesity rates are still fairly low overall, China and India are the most populous nations on the planet—with more than 2.5 billion people, combined—so even small percentage increases in obesity rates translate into millions more cases of chronic disease.

In China, from 1993 to 2009, obesity (defined as BMI of 27.5 or higher) increased from about 3 percent to 11 percent in men and from about 5 percent to 10 percent in women. Abdominal obesity (defined as a waist circumference of 90 centimeters or higher in men, and 80 centimeters or higher in women) also increased during this time period, from 8 percent to 28 percent in men and 28 percent of 46 percent in women. (19) That’s worrisome, since abdominal obesity may carry more serious metabolic consequences than overall obesity.

In India, meanwhile, recent data find that in 2005, nearly 14 percent of women ages 18 to 49 were overweight or obese, with higher rates among urban women (25 percent) than rural women (8 percent). The rate of overweight and obesity in women, overall, increased by 3.5 percent a year from 1998 to 2005. (4)

The Bottom Line: Turning Around the “Globesity” Epidemic

The worldwide increases in obesity over the past three decades have already led to increases in obesity-related chronic diseases, a trend that threatens healthcare systems, economies, and individual lives. Given the huge costs, both public and personal, of obesity—and how hugely difficult it is to lose weight once someone becomes obese—prevention is key. Slowing the increases in obesity and turning around the epidemic will take large-scale, multifaceted efforts, within individual countries and across the globe, to improve people’s food choices and increase physical activity. These efforts cannot begin in earnest soon enough.

Read more: obesity prevention recommendations | health risks of obesity | economic costs of obesity

References

1. Finucane MM, Stevens GA, Cowan MJ, et al. 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. Lancet. 2011;377:557-67.

2. Kelly T, Yang W, Chen CS, Reynolds K, He J. Global burden of obesity in 2005 and projections to 2030. Int J Obes (Lond). 2008;32:1431-7.

3. International Obesity Task Force. The Global Obesity Epidemic. 2010. Accessed February 29, 2011.

4. Popkin BM, Adair LS, Ng SW. Global nutrition transition and the pandemic of obesity in developing countries. Nutr Rev. 2012;70:3-21.

5. de Onis M, Blossner M, Borghi E. Global prevalence and trends of overweight and obesity among preschool children. Am J Clin Nutr. 2010;92:1257-64.

6. Doak CM, Adair LS, Bentley M, Monteiro C, Popkin BM. The dual burden household and the nutrition transition paradox. Int J Obes (Lond). 2005;29:129-36.

7. Belluck P. American Obesity Rates Have Hit Plateau, CDC Data Suggest. The New York Times.  January 14, 2012.

8. Nestle M. Good news: obesity rates leveling off. But how come? In: Food Politics; January 22, 2012.

9. Flegal KM, Carroll MD, Kit BK, Ogden CL. Prevalence of obesity and trends in the distribution of body mass index among US adults, 1999-2010. JAMA. 2012;307:491-7.

10. Wang YC, McPherson K, Marsh T, Gortmaker SL, Brown M. Health and economic burden of the projected obesity trends in the USA and the UK. Lancet. 2011;378:815-25.

11. Public Health Agency of Canada. Obesity in Canada: A Joint Report from the Public Health Agency of Canada and the Canadian Institute for Health Information; 2011.

12. Barquera S, Campos-Nonato I, Hernandez-Barrera L, et al. Obesity and central adiposity in Mexican adults: results from the Mexican National Health and Nutrition Survey 2006. Salud publica de Mexico. 2009;51 Suppl 4:S595-603.

13. Monteiro CA, Conde WL, Popkin BM. Income-specific trends in obesity in Brazil: 1975-2003. Am J Public Health. 2007;97:1808-12.

14. Doak CM, Wijnhoven TM, Schokker DF, Visscher TL, Seidell JC. Age standardization in mapping adult overweight and obesity trends in the WHO European Region. Obes Rev. 2012;13:174-91.

15. Musaiger AO. Overweight and obesity in eastern mediterranean region: prevalence and possible causes. J Obes. 2011;2011:407237.

16. Ng SW, Zaghloul S, Ali HI, Harrison G, Popkin BM. The prevalence and trends of overweight, obesity and nutrition-related non-communicable diseases in the Arabian Gulf States. Obes Rev. 2011;12:1-13.

17. Dalal S, Beunza JJ, Volmink J, et al. Non-communicable diseases in sub-Saharan Africa: what we know now. Int J Epidemiol. 2011;40:885-901.

18. Ziraba AK, Fotso JC, Ochako R. Overweight and obesity in urban Africa: A problem of the rich or the poor? BMC Public Health. 2009;9:465.

19. Xi B, Liang Y, He T, et al. Secular trends in the prevalence of general and abdominal obesity among Chinese adults, 1993-2009. Obes Rev. 2011.

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The aim of the Harvard School of Public Health Obesity Prevention Source Web site is to provide timely information about obesity's global causes, consequences, prevention, and control, for the public, health and public health practitioners, business and community leaders, and policymakers. The contents of this Web site are not intended to offer personal medical advice. You should seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this Web site. The Web site's obesity prevention policy recommendations are based primarily on a review of U.S. expert guidance, unless otherwise indicated; in other countries, different policy approaches may be needed to achieve improvements in food and physical activity environments, so that healthy choices are easy choices, for all.