About 2.1 billion people–or 30% of the world–is now overweight or obese, and the social impact is enormous. Obesity accounts for 5% of all deaths each year and generates costs equating to 3% of all gross domestic product. That’s as much as smoking, or the combined impact of armed conflict and terrorism.
What is worse, obesity’s impact is growing. As the developing world gets richer, it’s getting fatter. By 2050, half the world could obese or overweight, the report says.
What is the best way for the world to deal with this huge problem?
In a typically dispassionate way, a new study from McKinsey Global Institute analysis treats obesity has a grand “economics and business challenge” and looks at the potential solutions based on effectiveness and value-for-money. It identified 74 possible interventions–from labeling to public health campaigns–before narrowing the list to 44 for which there was sufficient data to make a judgment.
These fall into four categories: mechanisms that “inform” (e.g. color-coded labeling on food), “enable” (e.g. giving access to green-spaces or a gym), “motivate” (e.g. rewarding people through weight loss programs), and “influence” (e.g. changing the relative pricing of different foods).
McKinsey assessed how many healthy years of people’s lives they could save with each intervention (a measurement known as “disability-adjusted life years” or DALYs), then estimated the cost to achieve each. Overall, it found “portion control” had the highest impact–that is, food producers, restaurants and workplaces making smaller servings. The second most effective was “reformulation of fast food and processed foods”–where producers and restaurants quietly reduce food calories.
Interventions like parental education and changes in school curriculum to include exercise are highly cost-effective, the report says.
The study, which is based on U.K. health data, doesn’t indicate any idea is going to have a singularly dramatic effect. But it does suggest that “enabling” and “influencing” mechanisms– which work on people at a more subconscious level–may be more effective than “informing” and “motivating,” which are more conscious:
In general, we find that the interventions likely to have the most lasting effects are those that rely less on the volition of citizens and more on changes in their external environment, such as reducing portion sizes, reconfiguring promotional practices, or increasing compulsory exercise in schools.
McKinsey thinks we’ve relied too much on education and information in the past, and too little on the subtle signals that condition people to be unhealthy. Labeling food is a good idea, for example. But it relies on consumers to make better choices, which isn’t enough from a public health point of view.
“Subconscious mechanisms,” on the other hand, “serve to reset the default in order to make healthy behaviors easier and more natural,” the report says. That includes things like redesigning cities to allow more walking and cycling.
See more on the report here.