The world is getting fat. In many countries, the proportion of people at an unhealthy weight has more than doubled in the past few decades.1 Globally, at least 1.3 billion adults and more than 42 million children are overweight or obese.2
The consequences are considerable. Excess weight increases the risk of a wide range of illnesses, including diabetes, heart disease, and certain cancers; an estimated 2.6 million people die each year as a result of being overweight or obese. Some epidemiologists believe that excess weight will soon rival tobacco as the world’s leading cause of preventable premature deaths—the obesity pandemic’s health effects may wipe out the gains in life expectancy achieved through decreasing smoking rates.3
The obesity pandemic also has significant economic consequences. The World Health Organization estimates that in many developed countries, obesity now accounts for 2 percent to 7 percent of all health care spending.4 Yet medical costs are only a small fraction of the pandemic’s total costs. Among its other adverse economic effects are heightened absenteeism rates, reduced worker productivity, and increased food and clothing costs.
Although poor dietary choices and physical inactivity are important contributors to the pandemic, they are far from the only causes. A variety of other biological, psychological, cultural, economic, and environmental factors are also involved. (See sidebar “The many causes of obesity.”) The complex, interdependent relationships among these factors make it difficult for many people to control their weight—and for health care professionals, payors, other organizations, and governments to help them do so.
To identify approaches that might be effective in halting the pandemic, we conducted extensive research into the wide range of interventions that have been used to help people lose weight or maintain healthy weights, and we worked with the International Association for the Study of Obesity to evaluate policies that have been employed around the world to promote healthy weights. We found that the best results are achieved when entire communities join together to address multiple causes of obesity simultaneously. The communities create social movements that make healthy eating and exercise the norm.
To be successful, these social movements require the involvement of a wide range of stakeholders, including health professionals, payors, schools, employers, transportation authorities, food production and distribution companies, and the media. Although it can be quite difficult to enlist all these stakeholders, there are specific actions governments can take to encourage their participation in community efforts. Indeed, we believe that only governments—national, regional, and local—have the scope, scale, and mandate to ensure the participation and collaboration of all stakeholders. Governments are in a uniquely powerful position to encourage local organizations to undertake initiatives to promote healthy weights and to lay the foundation required to allow those efforts to succeed.
The pandemic’s health and economic costs
In almost all developed countries and in many developing ones, obesity rates have risen dramatically (Exhibit 1). Almost half of all US adults are obese. So are more than one-third of Mexican adults and one-quarter of adults in Australia and the United Kingdom. Even in sub-Saharan Africa, obesity rates are rising sharply, particularly among urban residents.5 Many developing countries now face yet another health dilemma: obesity rates are increasing even though many people remain significantly malnourished.
The consequences of rising obesity rates are considerable. Excess weight increases the risk of diabetes, heart disease, stroke, osteoarthritis, several forms of cancer (including esophageal, colorectal, breast, endometrial, and kidney cancer), and many other illnesses. (See sidebar “Saudi Arabia’s diabetes epidemic.”) As the prevalence of obesity rises, the prevalence of these conditions is also likely to rise. For example, the number of adults and children with type 2 diabetes is expected to increase sharply in coming years, particularly in developing countries, as a direct result of the pandemic. Furthermore, a person’s risk of death increases by almost one-third for every five-point rise in body mass index (BMI).6 In adults, obesity has been linked to a two- to four-year decrease in life expectancy; morbid obesity is linked to an eight- to ten-year decrease. The younger a person is when he or she becomes obese, the more years of life are likely to be lost.
The pandemic’s economic impact is equally severe. Many developed countries are already paying billions of dollars annually to manage the medical costs associated with obesity. Those costs are likely to escalate in the future, and not simply because obesity’s prevalence is rising. Our calculations reveal that medical costs are directly proportional to BMI; in the United States, every point of BMI above 30 is associated with about an 8 percent increase in a person’s annual health care expenses (Exhibit 2). Furthermore, obesity’s nonmedical costs are several times larger than its medical costs. (See sidebar “The economic impact of
the obesity pandemic.”)
A few recent reports suggest that in some countries, including the United States and the United Kingdom, the rate of increase in the prevalence of obesity is slowing. This is good news. However, unless these and the other nations find a way to lower their obesity rates, a growing number of their citizens will face an increased risk of chronic illness and premature death, and a rising percentage of their GDP will be spent coping with the pandemic’s consequences. For countries looking to rein in health care spending, reversing obesity’s rising prevalence is an imperative.
What works?
To identify the interventions that are most effective in helping people lose weight or maintain a healthy weight, we evaluated more than 1,000 studies published in the past ten years. The studies covered a wide range of approaches, including medical management, commercial weight-loss programs, and community-based health-promotion efforts. Our research revealed that single-intervention programs, such as low-calorie diets and exercise regimens, generally produce only modest weight loss. Better results are obtained when several interventions are used together. In addition to diet and exercise, the interventions can include nutrition classes, one-on-one counseling, drug therapy, bariatric surgery, and financial incentives.
The Dow Chemical Company, for example, randomly assigned half its work sites to a multipronged health-promotion program; the other half served as controls.7 At the intervention sites, employees were offered health assessments, educational materials, and online behavioral-change programs; in addition, they were given easier access to exercise (walking trails were built, for example) and provided with much healthier food choices in cafeterias and vending machines. At both one- and two-year follow-up, the company found that employees at the intervention sites had maintained their weight and BMI, whereas the employees at the other sites had increases in both metrics. Significant differences between the intervention and control sites were also found in average blood pressure and cholesterol levels.
The best results are achieved with multipronged programs that involve an entire community. For example, two towns in northern France (Fleurbaix and Laventie) undertook a regional initiative to reduce childhood obesity rates.8 They began by educating children about the consequences of obesity and the importance of healthy eating habits. In addition, they improved the food offerings in school cafeterias, provided nutritional family breakfasts at the schools, and started cooking classes for children and their parents. After a few years, Fleurbaix and Laventie expanded their efforts by hiring dieticians and a sports educator to create programs on nutrition and physical activity in the schools. They also built new sports facilities, launched walk-to-school groups, and developed family activities to promote exercise. Furthermore, they encouraged general practitioners to identify all overweight and obese children and refer them to the initiative’s dieticians, who then put the children on programs to help them lower their BMI. The towns also undertook an aggressive social-marketing campaign to promote healthy behaviors.
The results were striking (Exhibit 3). The prevalence of childhood obesity in Fleurbaix and Laventie decreased substantially—but it rose in nearby towns. The initiative was so successful that more than 200 other towns in France have adopted it; many of them have already reported marked decreases in the prevalence of children who are overweight or obese (Exhibit 4). The new program is dubbed EPODE—Ensemble, Prévenons l’Obésité Des Enfants (Together, Let’s Prevent Childhood Obesity). The methods Fleurbaix and Laventie developed have also been adapted for use in Belgium, Spain, and other countries.
On the other side of the world, the town of Colac, Australia, used a similarly comprehensive community approach to prevent excessive weight gain in its children.9 Colac put dieticians in its schools, improved cafeteria menus, and provided nutritional education for teachers, students, and parents. In addition, it increased the number of physical-activity programs the schools offered and inaugurated walk-to-school days. The town also worked to reduce the amount of time children spent watching television; it added lessons about this issue to the schools’ curriculum and used social marketing to promote a “TV power-down week.” Local community centers offered targeted programs to the parents of overweight and obese children.
Over the course of four years, the children of Colac improved their dietary habits significantly and increased their physical activity. As a result, the children in Colac gained considerably less weight than did the children in nearby towns.
Lessons learned
Our research confirms that successful weight-management programs, like most successful public-health efforts, have clear goals and clear ways to measure progress against those goals. They predefine their target population (children, adults, or both) and their objectives (whether to reduce the prevalence of obesity or to prevent further weight gain). They also carefully assess how well the various interventions are being used and what results are being achieved.
Three other important lessons can be drawn from successful programs to help people lose weight or maintain a healthy weight. First, there is no “silver bullet,” and short-term efforts have little impact. Successful programs use multipronged approaches that are sustained over several years. Second, customization is important, because the specific factors contributing to the obesity pandemic vary from area to area. In some cities, for example, there may be no open spaces available for recreation; in other cities, open spaces may be available but deemed too dangerous to use. In some rural and inner-city neighborhoods, there may be few supermarkets or other sources of healthy foods (these areas have been called “food deserts”). In other places, healthy food may be available but cost considerably more than less healthy choices. The interventions selected for a program should be targeted to primary problems in each locale.
Third, broad engagement is crucial—the program must involve a wide range of stakeholders throughout the community. For most people, behavioral change is difficult, and the forces contributing to the obesity pandemic are diverse and strong. As a result, a program will not succeed without widespread support. Among the organizations and individuals who should be involved are government officials, payors, health professionals, dieticians, physical-activity trainers and coaches, employers, schools, parents, community groups, retailers, restaurants, and the local media. Colac, Fleurbaix, and Laventie succeeded because their programs involved the entire community—they engendered social movements that made healthy behaviors the norm.
The uniquely powerful role of government
If locally led social movements can halt or reverse the obesity pandemic, why have there not been more of them? These movements often begin with small groups that are willing to take action to encourage healthy eating and exercise. However, many small groups are intimidated by the pandemic’s scope and complexity, as well as by the number of interventions needed to achieve impact. Several of the interventions require the organizers to push against entrenched interests in a range of interlocking areas: individuals want to relax and watch television rather than exercise; companies want to profit from their high fat, salt, or sugar products; television stations want to profit from the ads for those products, and so on. Small groups need support and encouragement to believe that they can take on these entrenched interests.
Payors (both public and private) can lend strong support to these groups; they can also undertake initiatives on their own to promote healthy eating and exercise. Their contributions can be invaluable. However, even very large payors lack the scope to address all the factors underlying the pandemic.
Governments—national, regional, and local—can play a uniquely powerful role in providing this support and encouragement and thereby catalyzing the creation of enough locally led social movements to change the pandemic’s course. They are in a singular position to offer incentives to, and align the efforts of, all the organizations that have a stake in this issue. Only governments have the authority to issue the policies and regulations needed to combat some of the forces contributing to the pandemic. Governments have responsibility for the health and economic well-being of their populations, and they must shoulder many of the pandemic’s costs. This is not to say that governments can succeed on their own, but we believe that only they can lay the foundation that will permit the efforts of small local groups to grow into community-wide social movements and make it easier for those movements to halt or reverse the pandemic.
What exactly should a government do? The first step is to make it clear to all that the obesity pandemic is one of its top priorities. Its efforts to promote healthy eating and exercise should be given visible, high-level leadership; a national government, for example, could appoint an “obesity czar.” This level of visibility will give local groups the encouragement they need to move forward.
In addition, the government should devote resources (money, staffing, or both) to these efforts at a scale commensurate with the pandemic’s severity. Adequate resources send another strong signal to local groups that the government is serious about the pandemic. From a pragmatic standpoint, the groups will need funding if they are to coordinate the multiple interventions required. (EPODE’s organizers estimate that the program’s coordination cost is between €2 and €4 per inhabitant per year, depending on the number of new interventions needed.)
How much money will be needed will vary significantly from country to country, depending on a number of factors, including the services already offered by local health systems and schools, the availability of sports facilities and other places to exercise, and the additional problems that must be addressed. On a per-person basis, the costs may not be high, but the aggregate cost may seem daunting at a time when many governments are suffering revenue shortfalls because of the global recession and loss of liquidity. However, the pandemic’s staggering health and economic costs clearly demonstrate that an adequate level of investment is necessary—even though the payoff on the investment may not materialize for several years.
Next, the government should use both incentives and mandates to make it easier for locally led social movements to overcome entrenched interests and achieve impact. In our work with the International Association for the Study of Obesity, we identified more than 40 policy levers that governments have employed successfully to encourage healthy eating and exercise. Obviously, no government can pull all of these levers simultaneously. We have therefore identified a smaller set of actions that we believe governments should take in six key areas: food production and standards, urban design and transportation, media, health systems, schools, and employers (Exhibit 5). These actions may require legislative or regulatory changes, but together they enable locally led social movements to make headway against the forces contributing to the obesity pandemic. And once these actions are under way, governments can consider taking other steps, depending on local needs and the availability of resources.
Whether incentives or mandates should be used for specific actions will often vary, depending on the type of government (national, regional, or local) considering the actions, and the sociopolitical environment within the country. In some countries, only national governments have the authority to ban trans fats from foods; in other countries, local governments may do so. Countries also differ when it comes to which governments have the right to restrict the location of fast-food restaurants near schools. Similarly, limits on the advertising of foods with high fat, salt, or sugar content may face greater legal challenges in some countries than others. Governments that do not have the authority to take certain actions can use incentives to promote the same ends.
In some cases, incentives may be more appropriate than mandates. Employers, for example, may respond better if they are given financial inducements to offer workplace nutritional counseling than if they are simply told to do so. The incentives can be positive or negative. Schools and health systems, for example, can be offered greater funding to enable them to implement certain actions; employers can be offered tax breaks. Negative incentives could include high taxes on sugary beverages and fees that discourage car use in cities.
Governments should also make sure that the incentives they use are aligned properly to ensure collaboration among stakeholders and to promote innovation. Obesity is a tough problem to deal with, and so it is crucial that existing interventions are tested in a wide range of settings and new approaches are tried. Governments can then use their convening power to help local organizations compare results and learn from one another. In addition, governments can monitor the results being achieved to keep alert for unintended adverse consequences (a rise in the prevalence of anorexia, for example).
Because of the obesity pandemic, today’s children may have a shorter life span than their parents do.10 The steps necessary to halt or reverse the pandemic are far from easy, but success is possible. We believe that governments must lay the foundation so that locally led social movements can shift cultural norms toward healthy behaviors. As a result, citizens will be healthier and health care costs will be less difficult to control.
About the Authors
Jeffrey Algazy, MD, MPH, a principal in McKinsey’s New Jersey office, is an internist by training and leads the Firm’s efforts in diabetes and metabolic diseases. Steven Gipstein, MD, an associate principal in the New Jersey office, is a pediatrician by training and a leader of McKinsey’s efforts on obesity. Farhad Riahi, MD, a principal in the London office, leads McKinsey’s work on clinical health economics. Katherine Tryon, MD, is an alumna of the Firm.
Notes