According to Chinese medicine, it's best to stay off the coffee in the afternoon. It's easier said than done, though - I'm drinking one right now, and it's gone 4pm!
Why Should We Drink Coffee In The Morning Rather Than The Afternoon?
Yang - the male energy, which is associated with heat, activity, daytime and summer - apparently rises throughout the morning, up to midday, when it's at its strongest. Coffee is a stimulant and a diuretic, so it works in harmony with your body's natural yang energy when drank in the morning.
However, if you drink coffee in the afternoon, you're swimming against the tide - although you're still running on Yang energy, it takes about 6 hours for the effects of coffee to leave your system, and your body will have already begun the transition into Yin (the female energy, associated with calmness, night-time, winter, and coolness).
Is It Bad To Drink Coffee In The Afternoon?
No, it's not bad - you just need to balance it with a drink that's Yin, such as water.
You don't have to stop drinking coffee in the afternoon, just make sure you're balancing it with something 'cool' or 'Yin', like fruit, vegetables, or water.