Rates of childhood obesity have declined in Philadelphia along with a few other cities. Though decreases are small, it is still welcome news after three decades of steadily increasing rates among kids. “If you blame the environment for the past 30 years, you have to credit the environment for what’s happening now. It’s great that the environment is changing and we’ve really started to see some declines,” said Gary Foster, director of the Center for Obesity Research and Education at Temple.