For a long time, people thought too much salt was bad for everybody, raising blood pressure and the risk of heart disease.
Then, studies found that some people could eat spoonfuls of salt without any noticeable short-term effects on blood pressure.
The new findings shed some light on who should be careful when it comes to salt.
It already was known that certain people should always be careful with their salt intakeÂ—older people, people with kidney problems and people with diabetes, for example.
Now, add overweight people to the list, especially overweight women and African-Americans with a particular gene that makes them salt sensitive.
A study out of Tulane University found that too much salt put overweight people at higher risk of heart disease and stroke. A study out of Wayne State University showed that blood pressure rose sharply in African-Americans with the salt-sensitivity gene who consumed as little as one extra gram of salt.
ThatÂ's not all that much. ThatÂ's just half a teaspoonful over the course of the day.