These long-term fiscal pressures lead political parties to fight ever more ferociously over shrinking resources. Simply put, the more the government must spend on health care and the more tax revenues it loses, the less there is for discretionary spending (such as education, highways, the environment and defense) and safety net services.

There are, of course, many causes of political conflict today. But our ability to negotiate differences within a large, diverse society will inevitably be undermined by rising economic pressures on families, communities and government and growing disparities in health and well-being.

With the couple hundred billion dollars of savings that could be achieved by rolling back obesity, Republicans could have tax cuts, Democrats could have increased social spending and the common ground for compromise would grow.

Seventy percent of American adults are at least overweight, and body weight is strongly influenced by biology; we can’t blame individuals and expect personal responsibility to solve the problem. Instead, we need the government to pass a suite of policy changes to encourage healthy diets.

Right now the government is doing the opposite. Farm policies have made low-nutritional commodities exceptionally cheap, providing the food industry with enormous incentive to market processed foods comprised mainly of refined grains and added sugars. In contrast, vegetables, whole fruits, legumes, nuts and high-quality proteins are much more expensive and, in “food deserts,” often unavailable. Processed foods are heavily advertised, even in educational materials directed at young children. And as cheap calories have flooded the environment, opportunities to burn off those calories at school, in recreation and through physically active modes of transportation have declined.

The broad outlines of a healthy diet are clear. A recent study in JAMA found that people can lose meaningful amounts of weight and lower their risk of heart disease by limiting sugar, refined grains and processed foods. Here are some steps that could move us from a disease-producing dietary environment to a health-promoting one:

First, establish a federal commission to coordinate obesity policy, which is now fragmented among numerous federal, state and local agencies. This commission would serve as a counterweight to the corrosive political influence and manipulative marketing practices of “Big Food” manufacturers.

Second, adequately fund obesity research into innovative approaches for prevention and treatment, beyond the conventional focus on eating less and moving more.