I switched to drinking tea instead of coffee, all day long. For the most part, I've noticed that I don't experience the afternoon slump as much. On the occasion

I switched to drinking tea instead of coffee, all day long. For the most part, I've noticed that I don't experience the afternoon slump as much. On the occasions that I do, a half cup of coffee usually overcomes it. I've also experimented with intermittent fasting, only eating between noon and 8pm. That also, for me, helped eliminate the slump.