Nearly 90% of adults consume more salt than U.S. dietary guidelines recommend. Now, federal officials are considering making those guidelines even tougher to follow.

Eating too much sodium, a key component of salt, can contribute to high blood pressure, a major risk for most people as they age because it can lead to heart disease and other health problems. But cutting sodium from the diet is difficult, mainly because people often don't know it's there. More than three-quarters of the sodium people consume comes from processed...