August 26, 2011 -- The rising prevalence of obesity around the globe places an increasing burden on the health of populations, on healthcare systems and on overall economies. A major challenge for researchers is to quantify the effect of these burdens to inform public policies. Using a simulation model to project the probable health and economic consequences from rising obesity rates in the United States and the United Kingdom, researchers at Columbia University's Mailman School of Public Health and Oxford University forecast 65 million more obese adults in the U. S. and 11 million more in the U.K. by 2030, leading to millions of additional cases of diabetes, heart disease, stroke, and cancer. The findings suggest that medical costs associated with treatment of these preventable diseases in the U.S. alone will increase by $48-66 billion per year.
The paper, "Health and Economic Burden of Projected Obesity Trends in the U.S. and UK," is part of a series of articles on obesity published in the August 27 issue of Lancet. The research was led by Y. Claire Wang, MD, ScD, Mailman School assistant professor of Health Policy and Management, with colleagues from Oxford University, Harvard University, and the UK National Heart Forum.
To construct historic trends in BMI the researchers analyzed data from two nationally representative surveys: the U.S. National Health and Nutrition Examination Survey (NHANES) from 1988 to 2008, and the Healthy Survey for England (HSE) from 1993 to 2008. The U.S. and U.K. have the highest obesity rates among the countries belonging to the Organization for Economic Cooperation and Development.
Projecting from these data sets: the researchers predicted the following impacts for the U.S. by 2030:
- Obesity prevalence among men would rise from 32% in 2008 to approximately 50% and from 35% to between 45% and 52% among women.
- 7.8 million extra cases of diabetes
- 6.8 million more cases of coronary heart disease and stroke
- 539,000 additional cases of cancer
- Annual spending on obesity-related diseases would rise by 13-16%, leading to 2.6% increase in national health spending.
- Total medical costs associated with treatment of these preventable diseases are estimated to increase by $48-66 billion/year.
For the U.K., researchers predicted the following developments by 2030:
- Prevalence of obesity among men would increase from 26% to between 41—48%, and among women from 26% to 35-43%.
- 668 000 more cases of diabetes
- 461,000 more cases of heart disease and stroke
- 139,000 additional cases of cancer.
- In the U.K., annual spending on obesity-related health would increase even more rapidly than in the U.S. due to its older population, rising 25%.
"Many chronic and acute health disorders associated with excess bodyweight burden society—not only by negatively affecting the health-related quality of life but also by incurring significant costs," says Dr. Wang. These stem not only from increased healthcare expenditures but also from worker absenteeism, disability pensions, less productivity at work due to poor health, and earlier retirement."
The new study shows that even a small drop in average body mass index (BMI) would have a major health and economic impacts. They therefore recommend action to promote healthier body weights.
"Taking no action would have the catastrophic consequences described in our study, but a population level decrease in BMI by 1% would avoid as many as 2.4 million cases of diabetes, 1.7 million cases of heart disease and stroke, and up to 127 000 cases of cancer in the U.S. alone ."
There are currently 99 million obese individuals in the U.S and 15 million in the U.K. The distribution of obesity is somewhat different in the two nations. In the U.S. about one-quarter of all men are obese regardless of ethnicity. Almost half of black American women (46%) are obese, compared with a third of Hispanic women and 30% of white women. In the U.K., the proportion of obese white men (19%) is slightly higher than black men (17%) and much higher than Asian men (11%). One-third of black women in the U.K. are obese, compared with 1 in 5 white women and 1 in 6 Asian women.
While there is some evidence that the rise in obesity is levelling off in some nations and possibly in the U.S., the jury is still out, says Dr. Wang. "Population weight changes are slow to manifest. Whether or not the U.S. and UK have turned a corner or plateaued will not be clear until survey results over the next few years provide additional data points."
The suggestion that obese people die earlier, thus saving the likely expected social and healthcare costs if that person survives to old age, is also discussed in the paper. However the authors conclude, "Without a doubt, healthcare expenditure is high for elderly people, but these costs should not be used to justify the cost-savings of dying younger, or to suggest that obesity prevention has no benefit."
The study was funded by the National Collaborative on Childhood Obesity Research, a joint effort of the National Institutes of Health, Centers for Disease Control and Prevention, Department of Agriculture, and the Robert Wood Johnson Foundation. Dr. Wang is also a contributing author on the two other related papers in the Lancet series, " The obesity pandemic: shaped by global drivers and local environments" and "A more realistic and accurate weight loss predictive model: 100 calories fewer per day would see weight loss of around 10 pounds over 3 years." The series was published ahead of the first ever UN High‑Level Meeting on non‑communicable diseases (NCDs) in September. "The inexorable global rise of obesity will be the toughest challenge that they face," noted the authors of the Lancet series.
About Columbia University's Mailman School of Public Health
Founded in 1922 as one of the first three public health academies in the nation, Columbia University's Mailman School of Public Health pursues an agenda of research, education, and service to address the critical and complex public health issues affecting New Yorkers, the nation and the world. The Mailman School is the third largest recipient of NIH grants among schools of public health. Its over 300 multi-disciplinary faculty members work in more than 100 countries around the world, addressing such issues as preventing infectious and chronic diseases, environmental health, maternal and child health, health policy, climate change & health, and public health preparedness. It is a leader in public health education with over 1,000 graduate students from more than 40 nations pursuing a variety of master's and doctoral degree programs. The Mailman School is also home to numerous world-renowned research centers including the International Center for AIDS Care and Treatment Programs (ICAP), the National Center for Disaster Preparedness, and the Center for Infection and Immunity. For more information, please visit www.mailman.columbia.edu