McDonald's Facebook page on July 27. Courtesy of McDonald's via Facebook hide caption

itoggle caption Courtesy of McDonald's via Facebook

D'oh! Forget the error on screen. Parking in front of it is the bigger mistake. iStockphoto.com hide caption

itoggle caption iStockphoto.com

Researchers looked at whether restaurants and stores that sold unhealthful food near high schools affected students' weight. M. Spencer Green/AP hide caption

itoggle caption M. Spencer Green/AP