With the nation’s attention still riveted on Obamacare, if we collectively remain focused on the health insurance component of health care, we could miss a crucial opportunity to improve the primary driver of our collective health: food.

Health care is important, yes, but it is not the only determinant of our well-being. The rest lies in what keeps us healthy, prevents chronic disease, and what the government subsidizes. As a physician, I find it inexcusable that the federal government’s principal nutrition program actually contributes to the largest health care crisis we have ever faced, not to mention the skyrocketing costs associated with treating our very sick nation.

Last month, an automatic, $5 billion cut to the Supplemental Nutrition Assistance Program (SNAP) took effect, substantially reducing benefits for poor Americans in every state. The debate over further program cuts rages on, but to save money and improve the health of low-income Americans we urgently need to implement more sweeping and fundamental changes in the farm bill.

We need these improvements to achieve the program’s original purpose as a strategy to improve nutrition, not just alleviate hunger. Somewhere along the way, we omitted the N in SNAP and lost sight of its intent. By distinguishing health from health care, junk from food, and band-aids from prevention, we can reduce costs and strengthen the program’s public health benefits.

Diet-related diseases are by far the leading cause of death in our country. The chronic illnesses that accompany the standard American diet — heart disease, diabetes, Alzheimer’s, even many cancers — are responsible for seven out of every ten deaths in the United States. The Centers for Disease Control estimates that almost half of American adults have at least one chronic illness, while more than a third of adults are obese.

These diseases are the largest strain on our health care system and, perhaps, on the federal budget. The direct costs alone are astronomical — well over a half trillion dollars every year — while the indirect costs through lost productivity and decreased quality of life are almost immeasurably massive. Medicaid, Medicare, and other taxpayer-funded programs pay for most of these expenses. The farm bill will affect nearly all of the range of factors that influence our health, and our health care expenditures will not be lowered with Obamacare alone.

These diet-related diseases follow a socioeconomic gradient, with the burden falling disproportionately on minorities and the poor — including SNAP participants. Poor Americans are more likely to suffer from chronic illness, and studies have even demonstrated a causal link between SNAP participation and obesity. One California survey, for example, found that obesity prevalence was 30 percent higher in SNAP participants compared with non-participants, even after controlling for other socioeconomic factors.

We urgently need systemic change, and the most effective way to save money while improving the health of low-income Americans is to reform SNAP. Congress should remove fatty meats and dairy, soda, candy and other junk foods from the program and trim the program down to a set of healthy, basic foods such as whole grains, beans, fruits and vegetables. The Physicians Committee for Responsible Medicine offers a healthy basics proposal that would result in cost savings from improved health far larger than the cuts themselves.

Although some have argued that these foods could be expensive or restrictive for SNAP participants, compared with the long-term health care costs that unhealthful diets incur, nutrient-dense staples such as brown rice, beans and vegetables cost very little. The program already excludes alcohol and cigarette purchases — why should nutrient-devoid, processed junk that sickens participants be any different?

Americans have ample reason to debate health care. We must, however, widen the scope of our discussion to include our actual health — and the farm bill and SNAP, which far too often function as a safety net for junk food manufacturers and the livestock industry while the poor slip through the cracks into an unbeatable cycle of chronic disease.

We have an opportunity to rectify this disservice to those who are among the most vulnerable. Let’s stop subsidizing sickness and instead use SNAP to help get our country back on track to physical and fiscal health.

Neal Barnard is president, Physicians Committee for Responsible Medicine.