The primary objective of this research is to identify the contribution of obesity to international differences in longevity. Adults in the United States have a higher prevalence of obesity than adults in any other country in Europe, North America, or East Asia. At the same time, life expectancy in the United States has fallen below that of most other OECD countries and ranked 32nd in the world in 2008. One of the prime candidates to account for the US disadvantage in health and longevity is its high level of obesity. A key input to evaluating the contribution of obesity to international differences in longevity is the set of individual-level mortality risks associated with different levels of obesity. This project will identify the set of mortality risks associated with obesity that should be used in international and intertemporal comparisons. We do so by explicitly introducing two other factors on which the mortality risks associated with current obesity depend: an individual's history of obesity and his or her smoking status. The omission of obesity histories from earlier studies has led to biased estimates of the effects of current obesity. Non-smokers show a higher mortality risk from obesity than smokers, so that countries that smoke heavily should be expected to have lower risks from obesity. We will apply these sets of obesity risks to calculate population attributable risks and obesity's implications for survivorship and longevity. An important product of our work will be an explanation of the large declines that have been observed in the estimated effect of obesity on mortality. In addition, we will develop a new indirect approach to estimating the contribution of obesity to international differences in longevity by building on previous methods developed to estimate smoking-attributable mortality. Epidemiologic and demographic studies of obesity would benefit greatly from a clarification of the mortality risks associated with obesity. Such a clarification would also contribute to improved projections of mortality in the US and elsewhere. Uncertainty about future of mortality is the single factor to which fiscal balances in the Social Security Trust Fund are most sensitive. The contribution of this project to improved projections is enhanced by its explicit incorporation of obesity histories into the risk analysis, since these histories are revealed well in advance of actual mortality conditions.

Public Health Relevance

The United States has the highest prevalence of obesity and one of the lowest life expectancies among developed nations. The objective of this research is to identify the contribution of obesity to international differences in longevity. Results will lead to improved mortality projections and a clearer understanding of how obesity is influencing national mortality profiles.

National Institute of Health (NIH)
National Institute on Aging (NIA)
Research Project (R01)
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Special Emphasis Panel (ZAG1-ZIJ-3 (M1))
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Patmios, Georgeanne E
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University of Pennsylvania
Social Sciences
Schools of Arts and Sciences
United States
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Ford, Nicole D; Narayan, K M Venkat; Mehta, Neil K (2016) Diabetes among US- and foreign-born blacks in the USA. Ethn Health 21:71-84
Stokes, Andrew; Preston, Samuel H (2016) How smoking affects the proportion of deaths attributable to obesity: assessing the role of relative risks and weight distributions. BMJ Open 6:e009232
Kelly, Laura A; Preston, Samuel H (2016) The contribution of a history of heavy smoking to Scotland's mortality disadvantage. Popul Stud (Camb) 70:59-71
Mehta, Neil; Preston, Samuel (2016) Are major behavioral and sociodemographic risk factors for mortality additive or multiplicative in their effects? Soc Sci Med 154:93-9
Stokes, Andrew; Preston, Samuel H (2016) Revealing the burden of obesity using weight histories. Proc Natl Acad Sci U S A 113:572-7
Cao, Bochen (2016) Future healthy life expectancy among older adults in the US: a forecast based on cohort smoking and obesity history. Popul Health Metr 14:23
Stokes, Andrew; Ni, Yu (2016) Validating a summary measure of weight history for modeling the health consequences of obesity. Ann Epidemiol 26:821-826.e2
Fishman, Ezra I; Steeves, Jeremy A; Zipunnikov, Vadim et al. (2016) Association between Objectively Measured Physical Activity and Mortality in NHANES. Med Sci Sports Exerc 48:1303-11
Mehta, Neil K; Elo, Irma T; Ford, Nicole D et al. (2015) Obesity Among U.S.- and Foreign-Born Blacks by Region of Birth. Am J Prev Med 49:269-73
Stokes, Andrew; Preston, Samuel H (2015) Smoking and reverse causation create an obesity paradox in cardiovascular disease. Obesity (Silver Spring) 23:2485-90

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