This article is part of a series presented by the American Prosperity Consensus in partnership with Slate. You can read the rest of the stories in this series here.

The future health and wealth of the country are inextricably tied. Right now, however, Americans are not as healthy as they could or should be, in large part due to the obesity epidemic. Obesity rates have more than doubled in the past 30 years. Two-thirds of adults and one-third of children are now overweight or obese. It is one of the biggest health crises the country has ever faced, and we’re at a crossroads for how we deal with it and where it will take our economy.

Obesity is among the biggest drivers of preventable diseases and health care costs in the United States. Estimates for these costs range from $147 billion to nearly $210 billion annually, with job absenteeism related to obesity costing another $4.3 billion annually.

In 2012, the Trust for America’s Health (TFAH) and the Robert Wood Johnson Foundation commissioned a modeling study which found that if obesity rates continue on their current trajectory, by 2030 combined medical costs associated with treating preventable obesity-related diseases could increase by between $48 billion and $66 billion per year. The loss in economic productivity could be between $390 billion and $580 billion annually.

Based on current trends, the nation would see a continued rise in the five most expensive conditions related to obesity: Type 2 diabetes, coronary heart disease and stroke, hypertension, arthritis, and obesity-related cancers (among other health problems).

The study also found that if obesity trends fell as a result of reducing the average adult body mass index (BMI) by 5 percent, millions of Americans could be spared from serious health problems and the country could save $29.8 billion in five years, $158 billion in 10 years, and $611.7 billion in 20 years.

Despite the importance of preventing poor health, to date there has never been a strong national focus on prevention to deliver the potential results. But recent evidence from communities across the country shows that if we make a concerted effort, we can change the trajectory. For instance, a 2008 study by the Urban Institute, New York Academy of Medicine, and the Trust for America’s Health found that an investment of $10 per person in proven community-based programs to increase physical activity, improve nutrition, and prevent tobacco use could save the country more than $16 billion annually within five years. That’s a return of $5.60 for every $1 invested. The nation simply has not invested enough in these types of community-based initiatives.

America faces two possible health futures. We can continue down our current path and resign millions of Americans to health problems that could have been avoided. Or we can invest in giving all Americans the opportunity to be healthier while saving billions in health care costs. This decision could become one of the defining issues in the nation for the next 30 years.

What do you think is the most pressing issue facing the United States over the next generation? Have your say in the comments section by clicking on the “comment” icon. Your contribution will help define the American Prosperity Consensus project. You can follow the project at america2040.com.