WASHINGTON (AP) — Michelle Obama used the power of her bully pulpit Wednesday to push food companies and television broadcasters to do more to promote healthier foods to children — and to do it faster. Research shows food marketing is a leading cause of childhood obesity because the ads and promotions lead impressionable kids to then pester their parents to eat what they saw on TV, consumer advocates say. The first lady cited a "cultural shift" taking place in America's eating habits, and highlighted as examples salad bars that are now in many school lunchrooms and kids' restaurant menus that...