New York City is pouring hundreds of thousands of federal dollars into television ads telling people they’re better off knocking back a glass of seltzer water or fat-free milk than chugging a soda — part of hundreds of millions of dollars from President Obama’s economic stimulus package devoted to getting Americans to change their behavior by eating more veggies, kicking cigarettes and picking up dumbbells. In the latest spot, part of a $870,000 stimulus-funded “Pouring on the Pounds” campaign, a narrator warns that while it may seem harmless to have “midmorning soda, a sweetened tea at lunch, a frozen coffee...