What is it like to go to bed hungry? What is it like to tell your family that there is not enough food to go around? How do you feed a family for a month, when your paycheck is barely enough to cover the mortgage?
These are questions many families are wrestling with across the nation. Fifty million Americans are "food insecure" and don't know where they will find their next meal, according to figures released by the United States Department of Agriculture in 2009. That means 17.2 million children are at risk of going hungry.
Michael Marcincin, 51, of Temple, Pa., his wife Dannie and their three girls are getting by.
Michael and Dannie Marcincin used to work at a local tannery.
"My last day was Dec. 31, 2004," he said. "Then the tannery moved to Mexico."
He hasn't had a full-time job since. He works part time in security at a local department store, and his wife works part time at a day care center. The family gets some government assistance in the form of food stamps.
"Many times after working only 31 hours a week, you get paid, you pay the bills, you have $6 left in your wallet," Marcincin told ABC News. "You don't have enough for food."
Marcincin and his wife often skip meals or reduce their own meal portions so their children can eat.
"They see we are not eating and they ask us why aren't you eating and we'll say well we are not hungry," he said. "The kids know. The whole family knows our situation."
New research has shown that children are much more aware of food insecurity and its effects on the family unit, according to John Cook, an associate professor of Pediatrics at Boston University's School of Medicine.
"They recognize very clearly that their parents are reducing their food intake to save them from experiencing hunger," Cook said. "It's distressing to them."
Children may come up with their own coping mechanisms.
"They express concern for their parents," Cook said. "They will even reduce their own food intake. They will undertake their own processes to contribute to the family's resources."
Food insecurity is a health risk, Dr. Megan Sandel, an associate professor of pediatrics and public health at Boston Medical Center, a colleague of Cook's, told ABC News.
"Not having enough food places children and parents at risk of malnourishment," Sandel said. "When you are underweight, you have a hard time fighting illness."
Having the proper nutrition through age 3 is crucial for brain development and social development, Sandel said.
"Between the ages of 0 and 3, children are developing the brain they are going to have for the rest of their lives," Sandel said. "Children who are not eating enough will conserve energy. They are less exploratory. They are not doing the kind of brain development that is necessary. They will sit. Parents who are not eating enough are not as able to interact with their child. They are less active. A lot of the important bonding and modeling will not take place."
Sandel added that there is a tendency for under fed children to become obese later in life.
Child hunger is not only a health problem, but an educational problem, as well, according to Feeding America, which provides food and groceries to people at risk of hunger across the nation.
In the classroom, children who are hungry through age 3 cannot learn as much as fast or as well because Feeding America says chronic under nutrition and toxic stress harm their cognitive development during a critical period of rapid growth.
Also, hungry children do not perform as well academically in school because they are not well prepared and have difficulties concentrating. They also have more social and behavioral problems.
"Food insecurity can also cause anxiety in children," said Karrie Denniston, vice president of national programs for Feeding America. "We see kids not wanting to leave the classroom on Friday. They are worried about how they are going to get a meal over the weekend. They feel anxious and are often embarrassed about the situation at home. They may not want to have friends come over because they cannot offer them something to eat."
Feeding America has a BackPack Program that provides children with nutritious and easy-to-prepare food when other resources are not available. The program provides backpacks filled with food that is "child-friendly," non-perishable and easily consumed. They are discreetly distributed to children on the last day before the weekend or holiday vacation. In 2010, 5.8 million packs were given to children in close to 5,000 locations, the organizations said.
Hunger relief agencies say the problem is no longer confined to the urban poor.
"More and more people are coming in" said Maria Delsordo, communications director for Philabundance, a Philadelphia-based hunger-relief agency. "We are seeing people coming in that never had to get food assistance before -- the newly unemployed, the underemployed, families that have at least one parent working."
Food relief agencies are working hard to let the people who need aid know they are not alone, she said.
"What people are saying is things are getting progressively worse," Delsordo said. "People who are new to the situation find it hard to tell their stories. They don't know who to turn to or where to go."
Michael Marcincin said that his daughters make the family's tough situation easier to deal with.
"They are good kids," he said, "overall good kids. They do their chores. They help out around the house."
As the school year approaches, he said he and his wife are preparing.
"I do know they are going to need school supplies and clothes," he said. "So we cut back. We don't cut back on them. You know, you eat one plate of spaghetti instead of two."
Marcincin said the key is sustaining and surviving.
"You don't give up," he said. "Keep going. If you give up, you are giving up on your family."