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Your Meal Has Six Times More Salt Than You Think

How much salt was in your lunch? Whatever your guess, chances are you’re off. By a lot.

In a new study, published in the journal Appetite, researchers stood outside fast-food restaurants and asked people to guess how much sodium they just ate. Their answers were almost always six times too low.

That's because people don't tend to use a lot of salt to season meals cooked at home, but restaurants use much more of it to enhance the flavor of their meals. It’s also used in food additives and as a preservative to extend shelf life, so even foods that don’t taste salty, like pastries, donuts and bread, can have a lot of it.

As a result, 89% of Americans eat too much salt. People should get no more than 2,300 milligrams of sodium a day—about one teaspoon, public health groups recommend—but the average American eats about 3,600 mg every day. Eating too much salt makes the body retain more water, which raises blood pressure and can affect the heart, blood vessels, brain and kidneys. Overconsuming sodium can lead to hypertension, heart attack and stroke, according to the Harvard T.H. Chan School of Public Health.

MORE: Here’s How Americans Are Failing to Meet Dietary Guidelines

To test the sodium knowledge of real-world eaters, researchers stationed themselves at several fast-food restaurants—McDonald’s, Burger King, Subway, Wendy’s, Kentucky Fried Chicken and Dunkin’ Donuts—and polled adolescents and adults on their sodium consumption. When people approached the entrance, the researchers asked them to save their receipts; on their way out, they estimated how much sodium they ate.

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