Fast food found to have much more sodium than once thought. In a new study published in the journal Appetite, researchers polled fast-food-restaurant-goers about the amount of sodium in what they just ate. In almost all cases, the guesses were six times lower than the actual amount. One reason the guesses were so off is that a lot of people tend to use a minimal amount of salt when seasoning their food, so they assume that restaurants are doing the same. As it turns out, 89 percent of Americans consume more salt than they are supposed to. While the recommended daily amount is 2,300 milligrams (around one teaspoon), most Americans eat 3,600 mg a day.