As the chief of epidemiology at a major medical school, I am frequently asked what the biggest threat is to the health of our nation. My response is obesity.

The obesity epidemic is a public health crisis in the U.S. Over one -third of all adults are obese; and another two thirds are overweight and on the way to becoming obese. In racial and ethnic minority groups including blacks, Hispanics and Native Americans, obesity has touched nearly half of the adult population.

That is why I cheered when I read the findings of a recent study describing how effective a beverage tax was on lowering the consumption of sugar-sweetened beverages in Philadelphia. 

The logical first line of defense against obesity is individual behavior changes to promote healthy lifestyles. However, individual behavior change is ineffective in the face of social and structural barriers that constrain individual choice. These barriers are uniquely relevant among racial and ethnic minorities and impoverished adults who are more likely to be obese.

Across a lifetime, obesity contributes to the development of physical illnesses including cardiovascular diseases and lung disease, mental illnesses such as depression, and disabilities including osteoarthritis.

Obesity is also responsible for perpetuating disparities in multiple chronic diseases by race, ethnicity and socioeconomic class.  For example, the disparate burden of obesity in blacks may explain elevated rates of heart failure and stroke in black men and women as compared with whites.

One reason why I support using sin taxes such as the sugared beverage tax to regulate unhealthy behaviors that contribute to obesity is because their reach is broader than individual interventions.

The “prevention paradox” as described by British epidemiologist Geoffrey Rose in a 1985 study that was republished in 2001, states that “large numbers of people must participate in a prevention strategy for direct benefit to relatively few.”

In the context of sugar-sweetened beverage taxation, it means that there is some truth in the grumblings of people who argue, “I do not have a weight problem, and the government should not infringe upon my rights.”

Yes, but the reason bans can work is because with the ban, some people stop and consider whether they actually need a two-liter bottle of juice—and whether they are willing to pay more to have it now.  For people on a budget—these negative incentives raise awareness and promote small behavior changes as seen in Philadelphia. Small changes can morph into lifestyle patterns that have a large effect on the environment and culture around obesity.

However, the most important reason that population-wide prevention measures work for obesity is because they can prevent the development of obesity in the first place. One of the most compelling arguments posed by medicine and public health agencies is that taxation can interrupt the alarming rise in childhood obesity.

I had a firsthand look at the origins of socioeconomic disparities in childhood obesity when we enrolled our child in a home-based daycare because it was much less costly than its commercial counterpart. Our daycare provider received subsidies from the state because she was serving a large population of low-income children. She used those subsidies to purchase food and beverages for the children.

During snack time, she served chips and juice to the children. Alarm bells went off for our family. The absence of policies restricting the use of state funds to feed children was a missed opportunity to avert bad lifestyle habits. Had there been a tax in place on sugared beverages, I wonder whether her purchasing patterns, and the children’s consumption patterns, would have changed.

We were able to move our son to a private university–run daycare that followed recommendations from the American Academy of Pediatrics to restrict sugared beverages from children, because we could afford to pay four times more for childcare.

Lower income and even middle-income families with children at the highest risk for obesity should not have to expose their children to obesigenic environments that will compromise their future health. When overweight children grow into obese adults, cycles of obesity and poverty continue because obese adults are subject to discriminatory hiring practices, lower salaries and restricted access to higher-status occupations, which ultimately limits their economic potential.  

To be certain, there are multiple factors contributing to obesity. Focusing solely on food ignores the role that sedentary behaviors, short and poor-quality sleep and stressful lifestyles have on obesity. Further, as we learned in the Flint water crisis, water is not always a safe beverage.

Despite significant pushback from individuals and even entire cities like the city of Chicago where I live that repealed a sugar-beverage tax shortly after its rollout, I remain convinced that these population-wide approaches are our best weapon against the epidemic of obesity.

However, a balanced portfolio of policies that attack “sinful” behaviors and promote “virtuous” behaviors will be most effective. Subsidizing healthy choices and providing access to those choices shifts the focus from what you cannot do to what you should—and provides specific guidance.

Policies and regulations targeting the environment are the least personally stigmatizing because they do not blame individuals for poor choices. Rather, they focus on creating environments where the healthy choice becomes the easy choice.

And that is no small matter.