Researchers say that childhood obesity rates are on the decline in Philadelphia and around the nation. "We're seeing it all across the country, so I believe it is a trend — not just in big cities…but in smaller cities throughout the country," said Gary Foster of Temple's Center for Obesity Research and Education. Foster credits efforts to change children's eating habits in school — and on the way home from school. "Snacking is a big part of American culture," he said. "In cities like Philadelphia, children walk out of schools and for $1.07 can purchase 360 calories in a corner store."