WASHINGTON, Sept 25: Former US military leaders have identified a latent threat to the potential for a leaner, more agile fighting force: the school vending machine. In a report to be released today, a group of 300 retired military officers said school-age children are eating 400 billion excess calories a year – the equivalent of 2 billion candy bars – from junk food sold in such machines as well as in snack bars and cafeterias that should be off-limits. (AGENCIES)