(AP) — In this May 3, 2006 photo, a student purchases a brown sugar Pop-Tart from a vending machine in the hallway outside the school cafeteria, in Wichita, Kan.

According to the first large study of states’ laws governing the sale of junk food and drinks in U.S. public schools, these regulations may help curb childhood obesity. (AP Photo/The Wichita Eagle, Mike Hutmacher)