Global Epidemic of Obesity June Stevens, MS, PhD University of North Carolina Chapel Hill
Outline Obesity and overweight prevalence rates in the United States Prevalence in diverse countries Environmental and social influences Global obesity link to global cancer What s coming?
We ve all heard about obesity in the U.S.
On TV
In Magazines
February 9, 2010, 1:33 pm Michelle Obama Leads Campaign Against Obesity By SHERYL GAY STOLBERG Luke Sharrett/The New York Times President Obama signed a memorandum on childhood obesity in the Oval Office with from left, Health and Human Services Secretary Kathleen Sebelius, Agriculture Secretary Tom Vilsack, First Lady Michelle Obama and Interior Secretary Ken Salazar.
United States Overweight: BMI 25-29.9 kg/m 2 Obese: BMI 30.0 kg/m 2 2/3 of adults overweight or obese 1/3 of adults are obese
U.S. From 1960 2 to 2005 6 prevalence of obesity steadily increased among both genders, all ages, all racial/ethnic groups, all educational levels, and all smoking levels Rates of increase lower since 1999, but the prevalence remains high
But the U.S. isn t alone or the world s most obese
Western Pacific
Overweight & Obesity Prevalence, Adults, Aged 15+, 2010 Rank Country Region Women Prevalence (%) Men Prevalence (%) 1 Nauru Western Pacific 93 96.9 2 Tonga Western Pacific 92.1 91.4 3 Micronesia Western Pacific 91.1 93.1 4 Cook Islands Western Pacific 90.3 93.4 5 Niue Western Pacific 86.7 80.9 6 Palau Western Pacific 84.5 77.2 7 Samoa Western Pacific 84.1 81.1 8 Barbados Caribbean 83.3 65.1 9 Dominica Caribbean 80.8 70.8 10 Trinidad and Tobago Source: World Health Organization, 2010 Caribbean 80.8 65.2
Many other countries and regions have >65% prevalence of overweight and obesity (W.H.O., 2010)
Central and South America
Mongolia
South Africa
United Arab Emirates Egypt
Europe
2002: Overweight and obesity rates
2010: Overweight and obesity rates
Brazil Repeated cross-sectional, population-based surveys (1975, 1989, 2003) Prevalence increased between each 14 year period 1975-1989: Men- 60% increase, Women- 50% increase All income groups 1989-2003: Distinct pattern with income in women (Monteiro, 2007 )
Brazil- (Monteiro, 2007) Women of highest income groups had a small decrease in obesity prevalence, while the lowest income groups continued to increase Secular trends in age-adjusted obesity prevalence rates by income 1975-2003 among women
Body Image Attitudes and Economic Development
Effect of Economy $2,500 per capita is the tipping point for the transition from higher rates of obesity in rich to higher rates in the poor (Monteiro, 2004)
Africa (Abubakari, 2008) Higher socio-economic groups found to have higher rates of obesity in West Africa. Body fatness is often considered desirable a sign of fertility, prosperity, and happiness
West African Countries Data- from a Meta analysis of studies from 1966-2007 on West African Countries Urbanization- increasing faster than any other region 4% of population moves to an urban area/ year By 2030- over 30% of the African population will live in urban areas (Abubakari, 2008)
Why is urbanization important? Decrease in Physical Activity Decrease in manual labor Change in transportation methods Change in food habits Decrease in meals prepared at home (inadequate kitchens, increase options out of home) Increased availability of energy-dense processed foods Increase in sugar and fat intake
West African Region- Urban men and women have a high prevalence rate of obesity compared to their rural counter parts (Abubakari, 2008) Urban women Rural women Urban men Rural men
Odds of Obesity in urban areas are higher than in rural areas in the West Africa countries of Cameroon (C), Ghana (G), and Nigeria (N) (Abubakari, 2008) 2.70 (1.76, 4.15)
Many developing countries have a higher prevalence of overweight than underweight in women 20-49y especially in urban areas. (Ranked by Gross National Income in 2009 dollars) (1a) Urban Women (1b) Rural Women Mexico [4440] Brazil [4320] S. Africa [3310] Turkey [3160] Namibia [2110] Peru [2080] Columbia [2020] Guatemala [1650] Jordan [1590] Domin. Rep. [1570] Kazakhstan [1290] Morocco [1100] Bolivia [1000] Egypt [990] China [710] Cote d'ivoire [660] Zimbabwe [630] Uzbekistan [630] Cameroon [610] Kyrgyz Rep [590] Senegal [520] India [440] Ghana [390] Zambia [360] C. African Rep. [360] Kenya [350] Benin [350] Nigeria [290] Burkina Faso [290] Haiti [270] Uganda [250] Madagascar [250] Mali [240] Malawi [220] Niger [200] Tanzania [190] 80 60 40 20 0 % Underweight 0 20 40 60 80 % Overweight Mexico [4440] Brazil [4320] S. Africa [3310] Turkey [3160] Namibia [2110] Peru [2080] Columbia [2020] Guatemala [1650] Jordan [1590] Domin. Rep. [1570] Kazakhstan [1290] Morocco [1100] Bolivia [1000] Egypt [990] China [710] Cote d'ivoire [660] Zimbabwe [630] Uzbekistan [630] Cameroon [610] Kyrgyz Rep [590] Senegal [520] India [440] Ghana [390] Zambia [360] C. African Rep. [360] Kenya [350] Benin [350] Nigeria [290] Burkina Faso [290] Haiti [270] Uganda [250] Madagascar [250] Mali [240] Malawi [220] Niger [200] Tanzania [190] 80 60 40 20 0 0 20 40 60 80 % Underweight % Overweight Overweight = BMI 25; underweight = BMI <18.5. Mendez, Monteiro, Popkin (2005): AJCN
China 1980- Chinese population considered to have an ideal BMI mean BMI 20, with less than 1% of population at either extreme. (James, 2008)
China Study of overweight prevalence in Chinese adults aged 45-79 (n=7,858) comparing 1991 to 2000. (Wildman, 2008)
China- BMI >25 prevalence increased in all groups from 1991-2000. (Wildman, 2008)
Why the shift? Diet includes more sweeteners, more edible oil, greater energy density of foods, and more animal products Lower prices on oil (20-50% of price 40 years ago), greater availability (James, 2008) Physical activity patterns are changing as fewer jobs require manual labor, transportation methods change, and urbanization increases Change from bikes to cars in China Globalization of the food market (Popkin, 2005)
Relative Risk (CI 95%) of obesity -- Esophagus, Gallbladder, Colorectum and Kidney Cancers in Men Cancer RR (95% CI)* High v low BMI Esophagus 1.76 (1.03-3.02) Kidney 1.55(1.36-1.76) Colorectum 1.40(1.32-1.48) Gallbladder 1.38 (1.01-1.89) Pancreas 1.76(0.90-3.45) Data: WCRF/AICR Policy and Action for Cancer Prevention adapted from table A3
Relative Risk (CI95%) of obesity on cancers in women Cancer Endometrium RR (95% CI)* High v low BMI 3.40(2.68-4.33) Gallbladder 1.88(1.60-2.21) Kidney 1.85(1.66-2.06) Pancreas 1.70 (1.09-2.64) Breast 1.26(1.09-1.46) Colorectum 1.06(1.02-1.10) Esophagus 2.13 (0.97-4.71) Data: WCRF/AICR Policy and Action for Cancer Prevention adapted from table A3 p.153
Effects of overweight and obesity on cancer US, UK, Brazil and China
The Prevalence of Overweight Plus Obesity (BMI > 25) Children Aged 6-17.9 and Overweight and Obese for Adults Aged 18 and Older U.S.A. U.K. Brazil China Popkin (2007)
Impact on Cancer 2007 WCRF/AICR Diet and Cancer Report Population Attributable Fraction- The proportional reduction in disease incidence that would be achieved in a population by eliminating the causal exposure
For example- Esophageal cancer in Americans PAF% = 35 Theoretically, there would be a 35% decrease in incidence of Esophageal Cancer in the U.S. if overweight and obesity were prevented.
PAF% for various cancer sites affected by body fatness Cancer Site USA UK Brazil China Endometrium 49 38 29 18 Esophagus 35 31 23 17 Pancreas 28 24 18 14 Kidney 24 19 13 8 Gallbladder 21 16 10 6 Breast 17 16 14 12 Colorectum 9 7 5 3 Data: WCRF/AICR Policy and Action for Cancer Prevention adapted from tables A2 and A4 p. 152-153
Total PAF% for cancer sites affected by body fatness USA UK Brazil China Total estimate (male) Total estimate (female) 20 18 13 11 19 16 13 12
United States In 2000, it was estimated that 14-20% of all cancer deaths, or over 90,000 deaths, could be attributed to overweight and obesity in US adults. (Calle, 2003)
Summary The U.S. is not alone- overweight and obesity is a global problem Obesity rates also high in diverse countries Complex associations between economic prosperity, culture and urban living with obesity Very likely that global increases in obesity will result in increases in certain types of cancers Esophagus, Pancreas, Gallbladder, Colorectum, Kidney, Breast and Endometrium
What s coming?