Worldwide Regional Differences in Obesity, Elderly, and COVID-19 Mortality: Do the Exceptions Prove the Rule?

Main Article Content

James A. Koziol Jan E. Schnitzer


Objectives. Obesity and old age are commonly assumed to be risk factors for COVID-19 mortality. On a worldwide basis, we examine quantitative measures of obesity and elderly in the populations of individual countries and territories, and investigate whether these measures are predictive of COVID-19 mortality in those countries. In particular, we highlight regional differences relative to obesity and elderly metrics, and how these relate to COVID-19 mortality.

Methods. In this retrospective, population-based study, we obtained data relating to percentages of obese or elderly individuals in 199 countries, as well as COVID-19 mortality rates in these countries. We used negative binomial regression analyses to assess associations between COVID-19 mortality rates and the putative risk factors, in six regions – Africa, Asia, Europe, North America, Oceania, and South America.

Results. We found significant differences between regions relative to COVID-19 mortality, as well as obesity and elderly population proportions. There were also substantial differences between countries within regions relative to proportions of obesity and elderly individuals, and COVID-19 mortality.

Conclusions. There are significant differences both between regions and within regions relative to COVID-19 mortality rates, as well as proportions of obese or elderly individuals. A global pronouncement that obesity and elderly constitute definitive risk factors for COVID-19 mortality masks the subtleties engendered by these intra- and inter-regional differences.

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KOZIOL, James A.; SCHNITZER, Jan E.. Worldwide Regional Differences in Obesity, Elderly, and COVID-19 Mortality: Do the Exceptions Prove the Rule?. Medical Research Archives, [S.l.], v. 11, n. 8, aug. 2023. ISSN 2375-1924. Available at: <>. Date accessed: 02 oct. 2023. doi:
Research Articles


1. Kang S-J, Jung SI. Age-Related Morbidity and Mortality among Patients with COVID-19. Infect Chemother. 2020;52:154-164.
2. Yanez ND, Weiss NS, Romand J-A et al. COVID-19 mortality risk for older men and women. BMC Public Health 2020;20:1742.
3. COVID-19: review of disparities in risks and outcomes. Public Health England, PHE publications gateway number: GW-1447, 2020.
4. Dessie ZG, Zewotir T. Mortality-related risk factors of COVID-19: a systematic review and meta-analysis of 42 studies and 423,117 patients. BMC Infect Dis. 2021;21:855.
5. Foo O, Hiu S, Teare D, et al. A global country-level analysis of the relationship between obesity and COVID-19 cases and mortality. Diabetes Obes Metab 2021;23:2697-2706.
6. Gao M, Piernas C, Astbury NM, et al. Associations between body-mass index and COVID-19 severity in 6·9 million people in England: a prospective, community-based, cohort study. Lancet Diabetes Endocrinol 2021;9:350-359.
7. Poly TN, Islam MM, Yang HC, et al. Obesity and Mortality Among Patients Diagnosed With COVID-19: A Systematic Review and Meta-Analysis. Front Med (Lausanne) 2021;8:620044.
8.. Starke KR, Reissig D, Petereit-Haack G, et al. The isolated effect of age on the risk of COVID-19 severe outcomes: a systematic review with meta-analysis. BMJ Glob Health 2021;6:e006434.
9. Dadras O, SeyedAlinaghi SA, Karimi A, et al. COVID‐19 mortality and its predictors in the elderly: A systematic review. Health Sci Rep 2022;5:e657.
10. Paravidino VB, Leite TH, Mediano MFF, et al. Association between obesity and COVID-19 mortality and length of stay in intensive care unit patients in Brazil: a retrospective cohort study. Sci Rep 2022;12:13737.
11. Sawadogo W, Tsegaye M, Gizaw A, Adera T. Overweight and obesity as risk factors for COVID-19-associated hospitalisations and death: systematic review and meta-analysis. BMJ Nutr Prev Health 2022;5:10-18.
12. Singh R, Rathore SS, Khan H, et al. Association of Obesity With COVID-19 Severity and Mortality: An Updated Systemic Review, Meta-Analysis, and Meta-Regression. Front Med (Lausanne) 2022; 13: 780872.
13. Habis Y, Alsilmi R, Alirbidi L, et al. Effect of Obesity on Clinical Outcomes in COVID-19 Patients. Cureus 2023;15: e33734.
14. Harris E. Most COVID-19 Deaths Worldwide Were Among Older People. JAMA 2023;329:704.
15. Tadayon NB, Rayner DG, Shokraee K, et al. Obesity as an independent risk factor for COVID-19 severity and mortality. Cochrane Database Syst Rev 2023;5:CD015201.
16. Wong MK, Brooks DJ, Ikejezie J, et al. COVID-19 Mortality and Progress Toward Vaccinating Older Adults — World Health Organization, Worldwide, 2020–2022. MMWR Morb Mortal Wkly Rep 2023;72:113–118.
17. World Health Organization Coronavirus Dashboard.
Accessed 17 March 2023.
18. World Bank DataBank. Population ages 65 and above (% of total population). Accessed 1 April 2023.
19. Renew Bariatrics Report: Obesity Rates by Country 2022. Accessed 17 March 2023.
20. Gardner W, Mulvey EP, Shaw EC. Regression Analyses of Counts and Rates: Poisson, Overdispersed Poisson, and Negative Binomial Models. Psychological Bulletin 1995;118:392-404.
21. Cameron AC, Trivedi PK. Regression Analysis of Count Data. Cambridge University Press: 1998.
22. Hilbe JM. Negative Binomial Regression. Cambridge University Press: 2007.
23. Koziol JA, Schnitzer JE. State Government Policy Responses to the COVID-19 Pandemic in the United States 2022-2022: Concordant Heterogeneity? Medical Research Archives, v. 11, n. 4, apr. 2023. ISSN 2375-1924. Available at: .