A healthy dose of salt may not sound like a particularly healthy choice. For many of us, it just sounds like a lot of salt. That's because "healthy" has come to mean more than just being in good physical shape.

So, how did a word associated with good health come to describe something substantial or sizable?

"Healthy" dates to the late 1400s, when it referred to being in good physical condition. By the late 1500s, it could also describe good mental or spiritual health. Then, speakers starting using "healthy" to describe an appetite, one that indicated someone was in good health.

That's how other things that were robust or sizable became "healthy."

That shift is evident in expressions like a "healthy dose of skepticism" or a "healthy respect for the law." Depending on the context, "healthy" can mean something appropriate or fitting, or it can suggest a considerable amount. Not every healthy dose is necessarily healthy in the literal sense.

The word "wellness" has undergone its own evolution. Although it dates back to the 1600s, its meaning broadened in the 1950s to encompass not just the absence of illness, but positive physical, mental and spiritual health. For more on "wellness," "healthy," and other words we use to talk about well-being, listen to the audio above.