For the longest time, hunger made 3-year-old Joe-anna Parks tiny and quiet.

Lack of enough food caused the condition called failure to thrive, keeping the Frankford girl underweight and unable to speak properly.

She couldn't even tell her mother when she needed to eat.

But treatment at Drexel University's Grow Clinic at St. Christopher's Hospital for Children has helped Joe-anna, who was grinning, running, and speaking more clearly Wednesday under a colorful mobile of giant butterflies in the hospital's atrium.

There, Mariana Chilton - a professor at Drexel's School of Public Health and the founder of the Grow Clinic - hosted clinic doctors and patients and representatives of Sesame Workshop, the nonprofit that produces Sesame Street.

To the delight of Joe-anna and other Grow Clinic alumni, Sesame Street's Elmo showed up to help publicize a national antihunger campaign.

"Elmo! Elmo!" shouted children dressed in their Sunday best, their enthusiasm enchanting adults enough to help them forget - for a moment, anyway - that St. Christopher's sits in one of the poorest, hungriest neighborhoods in the United States.

Chilton brought everyone back to earth.

"One in three people in this area doesn't have enough money for food," Chilton said. "Their children are more likely to be sick, become hospitalized, and not grow and develop well."

Six of 10 children younger than 3 who appear in the hospital's emergency room come from families wrestling with extreme hardship related to housing, utilities, or food, said Chilton, who runs Witnesses to Hunger, a program that enlists women in poverty to speak about the problem.

Throughout the United States, one in four children 5 and younger lives in a family without enough money for food, Chilton added.

Chilton, who often testifies about hunger before Congress, has shared her work with Sesame Workshop. In turn, to alert others to the plight of the hungry, it has created kits that include a booklet in which Sesame Street's Big Bird says the term "food pantry" for the first time. Another character explains, "A food pantry is a place we go to when we need help getting food."

Having a childhood icon talk about hunger is a big step in widening the national conversation about problems among people living in poverty, Chilton said.

The material also helps parents "guide children . . . to make healthier choices" for food, said Jeanette Betancourt, Sesame Workshop's vice president of outreach and educational practices, who attended the St. Christopher's event.

Families who suffer from hunger need help, said Sherita Parks, 33, Joe-anna's mother. She and Joe-anna were profiled in an Inquirer series on hunger in the fall.

Hans Kersten, the pediatrician who leads the Grow Clinic, said Joe-anna had been improving and should grow to nearly five feet.

Parks, who has had difficulty paying for enough healthy food for Joe-anna, added, "I give thanks to the Grow Clinic for showing me ways to make healthy foods, and to the Witnesses for helping me find fresh foods to feed Joe-anna."

Contact staff writer Alfred Lubrano at 215-854-4969 or alubrano@phillynews.com.