"When I eat and I see my mom and dad don't, I say, 'Why don't you eat?' " he said. "It makes me feel nervous and kind of sad and stuff.
"I worry about them. I try to give them my chicken nuggets."
Marcus Sr. gently turns down his son's offers and tells him not to fret. "As long as you guys eat, we're OK," he said he tells the boy. "Me and Mommy will find something."
As hard times get harder, they seem to press more unyieldingly on the poor.
"The whole life of someone economically stressed is a lot more fragile than before," said Bill Clark, executive director of Philabundance, the region's largest hunger-relief agency.
The agency has seen need in the Philadelphia area grow 22 percent over last year, and 66 percent since 2009.
For the poor, the increase in food prices means they must spend an extra $30 a month, a huge sum for low-income people, analysts say.
"I never thought I'd be where I am," said Mary Reed, 48, a married mother of two in Bellmawr, Camden County. Reed cares for an 8-year-old autistic son, and her 60-year-old husband was laid off from a warehouse job in 2008. She must frequent food pantries to get by. "I never thought we'd hit rock bottom like we did," she said.
While suffering is local, some global factors are causing food prices to rise, according to Ricky Volpe, a retail food specialist at the U.S. Department of Agriculture.
First, prices of commodities - staple crops such as wheat and corn - are up, according to Steve Reed, an economist with the information and analysis branch of the federal Bureau of Labor Statistics. Similarly, the price of fuel used to ship food is up.