NEW YORK (AP) — New York City begins a new era in nutritional warnings this week, when chain restaurants will have to start putting a special symbol on highly salty dishes. The average American consumes about 3,400 mg of salt per day, and public health advocates have cheered the measure as a smart step to make diners aware of how much sodium they're ordering. In recent years, New York City has pioneered banning trans fats from restaurant meals and forcing chain eateries to post calorie counts on menus.