IMAGINE having to ask your child, "Do you want to breathe, or do you want to eat?"

That's the situation described to me by a mother I met through my work here in Philadelphia. She described being at a hospital with her son, who'd experienced an asthma crisis. She explained how she was not allowed to leave the hospital with her child until she paid for a home nebulizer for her son. So she was forced to spend all the money she had - and put herself in debt to keep her son alive.

Lost in the pageantry, lewd commentary and accusations of this presidential campaign are the needs of millions of Americans facing the impossible decisions poverty brings.

That's why it's so important that a question rising to the top of an internet poll for Sunday's town hall-style debate sees air time: "How will you help 42 million Americans facing food insecurity?" Find the link here.

In Philadelphia, the dire relevance of this question should surprise no one. At the height of the recession in 2010, Philadelphia had the second-highest rates of hunger in the country, with 50 percent of the families with children reporting food hardship.

Our city has yet to recover from such hard-hitting times. We know this by looking at the well-being of Philadelphia's youngest children. They are the bellwether of our economy, political policies and communities.

Simply put, if young children aren't healthy, none of us are.

Here's your indicator: Between 2014 and 2015, the percentage of children under age 5 living in deep poverty increased from 36 to 37.2 percent. So, while many celebrated new census numbers that, on the surface, showed that overall poverty rates improved last year, the youngest children in Philadelphia are actually faring worse. These young children now number over 40,000 - enough to fill the seats at two Flyers games at the Wells Fargo Center.

Born in 2010 or later, the young children living in poverty here came into the world during the worst financial crisis we've experienced in decades. During this time, their parents weren't doing well and couldn't give their youngest children the best opportunity for a healthy start.

Food insecurity - the lack of access to enough food for an active and healthy life - has devastating consequences for young children. Through our research at St. Christopher's Hospital for Children - where we have interviewed more than 10,000 families since 2005 - we've found that children in food-insecure families have more hospitalizations, higher rates of poor child health and greater risks for delays in their cognitive social and emotional development than their peers.

Not all families living in poverty are food insecure, but poverty sets the tone for food insecurity. Twenty-six percent of people in Philadelphia are living below the poverty line. For a family of four, the poverty line is only $24,250 a year. That hardly covers basic expenses.

Imagine living in "deep poverty," which means living on half that amount. Among the nation's 10 largest cities, Philadelphia ranks highest for deep poverty. That ranking is haunting. On the ground, we know what this really means: risky, unhealthy trade-offs between paying rent and paying for child care, paying utilities vs. paying for groceries or trading food for medicine.

"Do you want to breathe, or do you want to eat?" is not an exaggerated question. It's a family trying to make a real, rational decision in an impossible situation.

Poverty can't be a back-burner issue discussed in vague terms. As we tune into the town-hall debate, let's remember that our next president will set the agendas for wages, education, housing and opportunities for Americans living in poverty. Poverty is not just a few numbers that go up or down on a piece of paper. For millions of Americans, it's as tangible as the air they breathe and the food they eat - or the decision of whether they get one or the other.

Mariana Chilton is the director of the Center for Hunger-Free Communities and professor and Drexel University's Dornsife School of Public Health.