What's Working to Reduce Obesity?

As we think about opportunities to address obesity, one popular approach is to intervene at the community level. Individual-level interventions like nutritional and weight-loss counseling have their place, but when we think about getting the biggest bang for the buck, communitywide interventions that can keep a wider swath of people healthy are an attractive approach. Over the last decade or so, we have seen lots of ideas tested here in New York and across the country to try to get people moving more and eating better: putting calorie information on menus, banning trans fats in restaurants, establishing bike lanes, sprucing up parks, getting rid of vending machines in schools.

A recent study by Drexel University researchers looked at a range of these types of natural experiments being introduced to reduce obesity and assessed their effectiveness.

The researchers found mixed results. Some interventions--like banning trans fats and improving sidewalks--were found to have a strong impact on obesity-related outcomes. Other popular approaches--like posting nutritional information in restaurants--were found to have little or no impact. And for some, such as improving parks and adding trails, the impacts are unclear; most existing research looks only at use of amenities (are more people going to the park or walking on the trails?) rather than whether the changes are leading to residents achieving a healthy weight.

What should we make of these findings? First, as is so often the case, we need more and better research to get a better sense of the impact of various strategies to reduce obesity in communities. This is still a relatively young field, and given the alarming rates of obesity and related conditions--more than 25% of New Yorkers are obese--it has been important to try out a range of interventions rather than waiting for all of the evidence to tell us what works best. But now that we are seeing experiments in communities, it is important that we measure and learn from those different approaches and understand where to place our best bets.

Second, these findings are a good reminder that different strategies may be needed for different populations, so we need rigorous research that tells us which approaches are most effective for the population at highest risk. Here in New York City, nearly every restaurant--and even the vendors at Yankee Stadium!--has posted calorie information. And those figures give me pause; I think about whether that hot dog and that beer are worth it, or I may choose to get a salad instead of a turkey sandwich when those calorie counts are staring me in the face. But I'm also not overweight, and I earn enough that I can afford healthy options and make meaningful choices. Those New Yorkers who are most vulnerable, and at highest risk of being overweight or obese, may not have the luxury of making the healthiest choice. So if menu labeling isn't working for the target population--as the Drexel research and other studies suggest--we need to find and test other ways to make the healthy choice the easy choice.

Third, we should be looking at the range of outcomes related to these interventions. Even if, for example, bringing supermarkets to low-income neighborhoods doesn't lead directly to reductions in residents' weight (a finding of several studies in the news recently), are other benefits accruing from those investments? We should consider taking a broad view of what it means for communities to be healthy, and look for the economic and social benefits of interventions, even if their intended purpose to reverse obesity rates is not achieved.

A related point: it gives me pause that we can get excited about a new cancer drug that extends life for an average cancer patient by three months, but we are disappointed when an effort to decrease weight has just marginal impacts. Is there or should there be a double standard for community programs compared to medical care interventions?

Finally, we need to be cognizant of the additive effect of interventions designed to reduce obesity in communities. If we can saturate a neighborhood with resources that make it easy, safe, and affordable to be physically active and to eat healthy foods, I would argue we have a better chance of success than if we introduced one proven approach (say, banning trans fats) in isolation. If a whole host of opportunities for moving more and eating better are present in a community, it becomes tougher to ignore; good health starts to become a neighborhood value, a point of pride, part of the culture. These cumulative effects make it more challenging to measure and assess the effectiveness of individual interventions, but it seems to me that if a whole slew of changes can add up to community-level change that is more than the sum of its parts, we will succeed in turning the tide of obesity.