How do you sweeten your coffee a healthy way?

Ok, taking one for team. I poured myself a half cup of hot coffee just now, added about a half teaspoon of butter, stirred it until the butter melted and then let it sit for about 30 seconds. Although there was a little something on the top, most of it seemed to dissolve. Taste-wise, I wouldn’t dump it out in the sink or anything if I really needed the caffeine. But to me if you want sweet coffee without calories, you add a packet of Sweet 'N Low and if you want some fat, you add cream. I think this problem was solved thousands of years ago by the Egyptians or Mesopotamians.