Every society and every era has its own major killers. The leading causes of death in America are dominated by chronic diseases – such as heart disease, cancer and diabetes – and injuries. The behaviors that lead to chronic diseases are few and familiar: smoking, physical inactivity, and unhealthy diet. Roughly a quarter of American adults still smoke, which is far too high, but smoking rates are falling, and there is broad agreement among public health experts about the ways to prevent smoking, with price increases through taxes, restrictions on smoking in public places, counter-advertising, and community mobilization.

But as smoking rates have fallen, obesity rates have skyrocketed. Now about a third of Americans are obese and another third are overweight. The best estimates are that obesity kills “only” 112,000 people a year, but that still puts it as the second leading underlying cause of death after smoking, and that doesn’t count the millions of people suffering from conditions like arthritis because of obesity. And with the number of people who are overweight rising each year, obesity may well overtake smoking in the not-too-distant future.

Unlike smoking, we don’t really know how to stop or even slow the epidemic of obesity. Of course, it is no secret that people gain weight because they take in more calories than they expend, but exactly how to get people to consume fewer calories or expend more is a problem that public health experts have yet to solve. The problem isn’t simply one of education or motivation: everyone knows they should eat less and exercise more, and these days no one wants to be overweight. Public health experts do agree that the fundamental cause of the problem is our environment. Our world simply makes it too easy to eat calories – calories that we are biologically driven to want – and expend too few. Snack-food vending machines, fast-food restaurants, television, and fear of crime probably all contribute to this. But exactly what features of our environment are most at fault and, more importantly, what we can do to change them are the things we don’t know but need to know to respond to this epidemic.

That is exactly why the Prevention Research Center at Tulane University has chosen to focus on the Impact of the Physical and Social Environment on Obesity. We conduct innovative research to learn exactly what features of our everyday world matter most and evaluate the effect of changes to the environment on eating habits and on physical activity. In doing that, we work with local policymakers, public health practitioners, and community members in New Orleans and Louisiana so that the questions we are studying are the questions most of value to them, and so that the results of our research are put in the hands of people who can use them to shape healthier communities.