One in five American children live below the poverty line, and o ver 2.9 million students live in households where they are unsure when they might get their next meal.

Around 30 million students around the country qualify for free or reduced cost school lunches through a federal program called the National School Lunch Program.

A New York Times report released in July shows how a new rule being proposed by the Department of Agriculture to restrict access to food stamps (one qualifier for free school lunches) could kick more than 500,000 students off their lunch plan.

States with the most students eligible for federally subsidized free lunches also tend to have the most cases of child poverty, INSIDER found.

INSIDER reviewed federal data to find out how dependent on free lunches students were in every US state, and t he top 10 most dependent were all based in the South.

Visit INSIDER's homepage for more stories.

If you've ever tried to complete a work day or study for a test on an empty stomach, you probably understand the importance of a healthy stable diet for success. For students, that fuel usually comes in the form of daily school lunches, yet, for millions of American children, paying for school lunch is a luxury they simply cannot afford.

A report released by UNICEF found one in five American children falls below the poverty line. Of the 35 countries the report analyzed, the United States ranked a shocking 34th when it came to child poverty. That all adds up to nearly three million American children officially recognized as food insecure by the US Department of Agriculture. When these children return home from school, the prospect of a hot meal waiting for them on the dinner table is far from certain. The lunch provided at school could be the only meal they eat all day.

A school lunch might not initially seem like an expensive line item, but those lunches can add up. In some cases, students and their families are taking on school lunch debt, sometimes with dire consequences. Earlier this month a school district in Pennsylvania threatened to have children removed from their families and sent to foster care if their parents did not pay off their lunch debt.

Luckily, many of these students can benefit from free and reduced-cost lunches through a federal subsidy called the National School Lunch Program. First formed in 1946 under the Truman Administration, the program has since expanded and helped fill the bellies of 30.4 million kids in 2016. Nearly 100,000 of an estimated 130,000 US schools voluntarily participate in the program. Public schools and non-profit private schools all around the country receive cash subsidies from the federal government and use those subsidies to provide lunches to students free of charge.

According to the US Department of Agriculture, any student in a participating school can get an NSLP lunch regardless of the student's household income. Eligible students can receive free or reduced-price lunches: Free lunches are available to children in households with incomes at or below 130 percent of poverty. Reduced-price lunches are available to children in households with incomes between 130 and 185 percent of the poverty threshold. (The poverty threshold for a single person is $12,448. That number increases depending on how many children are in the family. The threshold for a family of five, for example, would be $30,170). In addition to household income, students also automatically qualify for free lunches if they come from a family already receiving food stamps.

INSIDER looked at federal data to see which states had the most students dependent on free or reduced cost school lunches. The results tended to be on par with those particular state's child poverty rates. See which states have the highest percentage of children dependent on free lunches and where your state stacks up.