One in two American children will be on the USDA’s Supplemental Nutrition Assistance Program (SNAP) at some time in their lives; one in four goes to bed hungry every night. In 1980 there were 200 food banks in the U.S.; today there are 40,000. Fifty million Americans live in a state of “food insecurity”—undernourished and unsure where their next meal is coming from.

That is the message of a remarkable 2011 documentary, “A Place at the Table,” in which filmmakers Kristi Jacobson and Lori Silverbush introduce us to hardworking people caught in a food crisis. A young mother in Philadelphia struggles to stretch her SNAP benefits to feed her two children. Overjoyed when she lands a job, her pride turns to despair as she realizes her paycheck leaves her with even less food for her children. A short order cook in Mississippi takes home $128 every two weeks, too much to qualify for food assistance.

A Colorado schoolteacher volunteers at a food bank. Sensitive to the embarrassment many feel about receiving charity, she discreetly places the bags of food in their cars or on their porches. She feels guilty because she knows that much of what she’s delivering is processed and junk food, not good nutrition.

We watch in 2010 as Congress passes the Healthy Hunger-Free Kids Act, which increased school lunch funding by $4.5 billion over 10 years (about six cents per meal) and raised nutrition standards. Lost in the ensuing back-patting is the fact that all of the increased funding came from cuts in SNAP. Out of the $2.68 budgeted per child for the school lunch program, only $0.95 goes to the actual purchase of food; the rest is administrative costs.

The problem is not food scarcity—we live in a land of abundance. But for a huge number of Americans, hunger is framed in failed food policy, a misguided system of federal farm support and extraordinary misconceptions about who needs help and why. It’s not only a question of quantity, but of the quality of food we are feeding our children, and the enormous health problems that result.

U.S. agribusinesses spend $124 million a year lobbying. Since 1995, we have spent $250 billion in farm subsidies, and 70% of that support has gone to just 10 agribusinesses that control what foods are available. The result: 84% of subsidies go to commodity crops like corn, soy and wheat; virtually zero goes to fruits and vegetables.

Our fellow citizens are caught in a spiral of poor nutrition, chronic anxiety and ill-health. Most disgraceful is the way we are shortchanging our children. Poor nutrition is directly linked to a range of physical, emotional and developmental issues. Our current system of food subsidies supports bad nutrition at the expense of our children’s health and ability to succeed.

Most people remain on SNAP for less than a year. They are there because of layoffs, family disruptions or medical emergencies. As they move to work, they need a transition period of support. Charity is admirable, but it can’t be a permanent solution, and the logistics of food charity make it difficult to provide fresh fruits and vegetables. We need a living wage. We need a comprehensive food policy that moves from food charity to fair access and puts nutrition first.

I can’t imagine an issue in which sustainability and social justice are more closely intertwined.