The food and advertising industries have launched a multi-pronged campaign to squash government efforts to create voluntary nutritional guidelines for foods marketed to children. Calling themselves the Sensible Food Policy Coalition, the nation's biggest foodmakers, fast-food chains and media companies, including Viacom and Time Warner, are trying to derail standards proposed by four federal agencies. The U.S. Chamber of Commerce has also lent its lobbying muscle to the effort. The guidelines are designed to encourage foodmakers to reduce salt, added sugars and fats in foods and drinks targeted to children. Public-health experts say children, many of whom may lack the critical-thinking skills to understand advertising, are bombarded daily by television ads, Web sites, toy giveaways and cartoon characters promoting junk food. The food and beverage industry spends about $2 billion a year marketing directly to children. The business community has portrayed the government's guidelines as job-killing government overreach. We allow companies into our homes to manipulate children to want food that will make them sick," said Margo Wootan of the Center for Science in the Public Interest.