Food Deserts in Los Angeles

"It's a real problem, says Cheryl Resnik, assistant professor of clinical physical therapy at the University of Southern California in Los Angeles, which abuts Perez's neighborhood.

Many of her students come to class either malnourished or jittery from sugar in sodas and fast food, she says.

"We were teaching them how to eat better, but then we realized they don't have access to the kind of food they need," says Ms. Resnik, who runs a free clinic. "The only thing they have are mom-and-pop liquor stores with candy bars and cupcakes.""