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Epidemiology of Obesity. A Global Pandemic. Joan Temmerman, MD. Stages of Epidemiologic Transitions. Gaziano, JAMA 2010;303(3). 1 st (most of human history): pestilence & famine Infectious disease & malnutrition average life expectancy 30 yrs
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Epidemiology of Obesity A Global Pandemic Joan Temmerman, MD
Stages of Epidemiologic Transitions Gaziano, JAMA 2010;303(3) 1st (most of human history): pestilence & famine • Infectious disease & malnutrition average life expectancy 30 yrs 2nd (late 19th & early 20th century): receding pandemics: industrialization & urbanization • increasing wealth, food availability, better nutrition, water & sewer systems decreased mortality, increased life expectancy
Stages of Epidemiologic Transitions 3rd (mid 20th century): degenerative & human-made diseases • increasing disease fromCVD (cardiovascular disease) & cancer; smoking, decreased activity, increased fats and animal products 4th (mid 1960’s): delayed degenerative diseases - - decreased CVD mortality, better prevention and technology
5th stage: The age of obesity & inactivity • Threatens steady gains in longevity & QOL
The age of obesity & inactivity • If trends continue, almost half of US adults will be obese by 2020 • Significant progress in decreasing chronic disease rates during last 40 years will be overturned • Possibly decreased life expectancy Gaziano, JAMA 2010;303(3)
Obesity Trends* Among U.S. AdultsBRFSS,1990, 2000, 2010 (*BMI 30, or about 30 lbs. overweight for 5’4” person) 2000 1990 2010 No Data <10% 10%–14% 15%–19% 20%–24% 25%–29% ≥30% Source: Behavioral Risk Factor Surveillance System, CDC
Obesity is a pandemic! Obesity affects all ages and socioeconomic groups Threatens to overwhelm both developed and developing countries (WHO) Pandemic refers to a worldwide epidemic. Although typically used in context of infectious diseases, it can describe chronic diseases as well.
Obesity pandemic • Global: affecting almost all countries with enabling economic conditions • Rapidly transmissible (near simultaneous upswing of the epidemic across countries over the past 40 years Swinburn BA et al; Lancet. 2011 Aug. 27;378(9793):803-14
Global prevalence-adults • In 2005 WHO estimated1.6 billion adults worldwide overweight; >400 million obese • By 2015 2.3 billion overweight; >700 million obese projected Nguyen & El-Serag, Gastroenterol Clin North Am. 2010
Global prevalence-children • Estimated 170 million children (<18) globally overweight or obese in 2008 • This is >25% of children in some countries! Swinburn BA et al; Lancet. 2011 Aug. 27;378(9793):803-14
Estimates of percentage of childhood population overweight and obese in a selection of countries Swinburn BA et al; Lancet. 2011 Aug. 27;378(9793):803-14
Global prevalence • Poor increasingly burdened • Paradoxically coexists with undernutrition (WHO) • Many countries in transition faced with doubleburden of undernutrition as well as overnutrition, obesity, & related diseases • The higher the level of income inequality, the higher the prevalence of obesity independent of the overall wealth of a country Swinburn BA et al; Lancet. 2011 Aug. 27;378(9793):803-14
• Obesity associated with increased mortality • 2-3-fold increased risk of death Serious health effects: obesity major risk for DM, CVD, HTN, stroke, and some cancers James WPT, J Intern Med 2008:336-352 Nguyen & El-Serag, Gastroenterol Clin North Am. 2010 Obesity strongly related to the epidemic of type 2 diabetes.
Strong link between obesity and T2DM 93-fold increased risk 42-fold increased risk Marrero DG. J Diabetes Sci Technol 2009;3(4):757-760.
Financial burden • Total annual economic cost of overweight & obesity in US and Canada caused by medical costs, excess mortality and disability was approximately $300 billion in 2009 Obesity and its Relation to Mortality and Morbidity Costs.” December 2010
What is driving this? What is driving this?
Dietary changes since 1970’s: US • Types of sugar: fructose • Sweetened beverages • Salty snacks, pizza, pasta, cakes, bread, cereals • Energy from snacks 50% • Food away-from-home 40% eaten outside home Gibson & Shepherd, Aliment Pharmacol Ther 2005;21
Shift in dietary patterns • More women working; single households • Decreased cooking skills taught in schools • Consuming prepared meals rather than cooking • Dependency on manufactured, processed foods • Tremendous shift to eating outside the home James WPT, J Intern Med. 2008;263:336-352
American trends • 50% of US food expenditure is now spent on food outside the home • Eating out is associated with obesity Clauson & Leibtag, USDA 2011
Trends in restaurant expenditures and obesity in the United States, 1940–2004. Sources: Flegal et al.& Ogden et al; USDA Food Expenditure Tables. Neil et al, Am J Prev Med. 2008 February ; 34(2): 127–133
Eating out increases calorie intake, worsens dietary quality • Poorer diet quality (more calories, fats and carbohydrates) & larger portion sizes compared to foods at home • People select more indulgent food when they eat out: more calories, fat, and saturated fat than at-home meals and snacks Todd & Mancino, 2010; Neil et al; 2008 Glanz et al, 2007; Mancino et al, 2009
The American Lifestyle • 50% of US food budget is spent eating outside the homeClauson & Leibtag,USDA 2011 • Only 9% keep track of caloriesand can accurately estimate how many calories they should eat • Physical activity has disappeared IFIC Foundation Releases 2011 Food & Health Survey • 40% of adults get no activity at all!
What is the global driver? • What is the environmental factor that has changed substantially over the past 40 years (coinciding with the upswing of the epidemic)? Swinburn BA et al; Lancet. 2011 Aug. 27;378(9793):803-14
Causes • Energy imbalance: dietary changes and decreased physical activity (PA) • Reduced heavy work; increased motorized transport, cheaper cars, technological aids to remove physical demands at home & work • Increased computer and TV time Possible to earn good wages & have enjoyable leisure with virtually no PA! James WPT; J Intern Med. 2008;263:336-352
Globalization • Penetration of Western-style media and fast-food outlets into developing world • US not only has highest obesity rates, but has led transformation of society to toxic “obesogenic” environment • Globalization of Western food systems and consumer culture has infiltrated all world societies James WPT, Int J Obesity 2008;32:S120-126 Sobal J, Int J Epidemiol. 2001;30(5):1136-1137.
What is Globalization? • Increased mobility of goods, services, labor, technology and capital throughout the world • Process of worldwide integration & unification • World considered a global unit Huneault et al, Obes Rev. 2011;12(5): e64-72 Sobal J. Int J Epidemiol. 2001;30(5):1136-1137.
Globalization • Globally decreased activity: universal & inexpensive transportation, cars, TV, energy-saving components of built environment • Global food systems & global vehicles, appliances and mass media are underlying causes of increases in global obesity Sobal J, Int J Epidemiol. 2001;30(5):1136-1137.
Urbanization • Industrialization and computerization almost totally replacing physical work • Small gas-powered systems for ploughing and other activities • Reduced cost of producing & distributing food Huneault et al, Obes Rev. 2011;12(5): e64-72 Popkin BM, Nutr Rev. 2009;S79-82
Global nutrition transition • Shift from traditional plant-based foods to more energy-dense diet • High in animal fat, sugar, processed, less fiber Kimokoti & Millen, J Am Diet Assoc. 2011;11(8):1137-40
Global transitions • Reductions in time-cost of food is major driver of global obesity epidemic • Rural urban • Infectious diseases non-communicable • Technological: low high mechanization and motorization • Traditional foods more processed, energy-dense Swinburn BA et al, Lancet. 2011 Aug. 27;378(9793):803-14.
Dietary changes • Energy-dense, cheap, tasty, highly accessible food • Highly effective marketing to buy immediately available food for instant gratification • Massive agricultural subsidies (fruit and vegetables least) • Cheaper meat, butter, oils, fats, sugars James WPT, J Intern Med. 2008;263:336-352
Global corporations • Establishing industrialized food systems providing 24-7 consumer access to unlimited volumes of cheap, calorie-dense foods • All people, all places, all times via supermarkets, vending, drive-throughs, catering, home-delivered, fast/snack foods Sobal J, Int J Epidemiol. 2001;30(5):1136-1137.
Technological changes creating cheaper, more available food + Strong economic forces driving consumption Overconsumption & obesity = Swinburn BA et al; Lancet. 2011 Aug. 27;378:803-14
Global solutions • Obesity represents a worldwide epidemic, therefore is a global pandemic • Not a set of independent occurrences in various nations • Global conditions have underlying global causes • Require global interventions Sobal J, Int J Epidemiol. 2001;30(5):1136-1137.
Areas for future public health efforts • Obesity must be recognized as major public health issue across the world • Recognition of obesogenic environment as main driver • Government leadership, regulation, investment to tackle toxic environment • Global priority for population-based policies promoting optimal nutrition • Consumer education, individual behavior
Policy changes: a sustained worldwide effort • Interventions to reverse obesogenic drivers must be predominantly policy-led: mainly government policy (shifting agricultural policies to incorporate health outcomes, banning unhealthy food marketing to children, healthy food sector service policies) • Also address built environment, transport systems, active recreation opportunities, food culture. Swinburn BA et al; Lancet. 2011 Aug. 27;378(9793):803-14) Hill JO et al, Obes Rev. 2008;9(S1):41-47
A framework to categorize obesity determinants and solutions Layers of determinants Distal Systemic; environments Proximal behaviors Swinburn BA et al; Lancet. 2011 Aug. 27;378(9793):803-14
Sustained worldwide effort • Many parties (governments, international organizations, the private sector, and civil society) need to contribute complementary actions in a coordinated approach. • Prioritize policies to improve food and built environments, cross-cutting actions (leadership, healthy public policies, and monitoring), and much greater funding for prevention programs. • Increased obesity monitoring in populations • Integration of actions within existing systems into both health and non-health sectors (trade, agriculture, transport, urban planning, and development) to augment the influence and sustainability of policies. Gortmaker SL et al, Lancet. Aug. 27;378: 838–847
References • Gaziano JM. Fifth phase of the epidemiologic transition: the age of obesity and inactivity. JAMA. 2010;303(3):275-276 • Obesity trends among US adults; Behavioral Risk Factor Surveillance System, CDC. Accessed 12/2/11 at http://www.cdc.gov/obesity/data/trends.html • Swinburn BA, Sacks G, Hall KD, McPherson K, Finegood DT, Moodie ML, Gortmaker SL. The global obesity pandemic: shaped by global drivers and local environments. Lancet. 2011 Aug. 27;378(9793):804-14. • Nguyen DM, El-Serag HB. The epidemiology of obesity. Gastroenterol Clin North Am. 2010 Mar;39(1):1-7. • James WPT. The epidemiology of obesity: the size of the problem. J Intern Med. 2008;263:336-352 • Marrero DG. The prevention of type 2 diabetes: an overview. J Diabetes Sci Technol 2009;3(4):756-760. • Obesity and its Relation to Mortality and Morbidity Costs.” December 2010. Accessed 12/2/11 at: http://www.soa.org/files/pdf/research-2011-obesity-relation-mortality.pdf • Gibson PR, Shepherd SJ. Personal view: food for thought-western lifestyle and susceptibility to Crohn’s disease. The FODMAP hypothesis. Aliment Pharmacol Ther 2005;21:1399-1409 • Clauson A, Leibtag E. Food CPI and Expenditures Briefing Room. Table 12. US Department of Agriculture. www.ers.usda.gov/Briefing/CPIFoodAndExpenditures/Data/Expenditures_tables/table12.htm. Accessed May 10, 2011 • Neil K. Mehta NK, Chang VW. Weight Status and Restaurant Availability: A Multilevel Analysis. Am J Prev Med. 2008 February ; 34(2): 127–133
References • Todd JE, Mancino L. Eating Out Increases Daily Calorie Intake Amber Waves June 2010. USDA ERS. http://www.ers.usda.gov/AmberWaves/June10/Findings/EatingOut.htm • Glanz K, Resnicow K, Seymour J, Hoy K, Stewart H, Lyons M, Goldberg J. How major restaurant chains plan their menus: The role of profit, demand, and health. Am J Prev Med. 2007 May;32(5):383-8. • Mancino L, Todd J, Lin BH. Separating what we eat from where: Measuring the effect of food away from home on diet quality. Food Policy 2009;34(6):557-562. • International Food Information Council (IFIC) Foundation. http://www.foodinsight.org/Press-Release/Detail.aspx?topic=Price_Approaches_Taste_as_Top_Influencer_for_Americans_When_Purchasing_Foods_Beverages Accessed May 26, 2011 • James WPT. WHO recognition of the global obesity epidemic. Int J Obesity 2008;32:S120-S126. • Sobal J. Commentary: Globalization and the epidemiology of obesity. Int J Epidemiol. 2001;30(5):1136-1137. • Huneault L, Mathieu ME, Tremblay A. Globalization and modernization: an obesogenic combination. Obes Rev. 2011 May;12(5):e64-e72. • Popkin BM. What can public health nutritionists do to curb the epidemic of nutrition-related noncommunicably disease? Nutr Rev. 2009;27(S1):S79-82. • Kimokoti RW, Millen BE. Diet, the global obesity epidemic, and prevention. J Am Diet Assoc. 2011 Aug;111(8):1137-40. • Hill JO, Peters JC, Catenacci VA, Wyatt HR. International strategies to address obesity. Obes Rev. 2008;9(S1):41-47. • Gortmaker SL, Swinburn BA, Levy D, Mabry PL, Finegood DT, Huang T, Marsh T, Moodie ML. Changing the future of obesity: science, policy, and action. Lancet. Aug. 27;378: 838–847.