Coffee does increase the metabolism. The way to maintain it’s holistic effect on the metabolism is often left out in the mainstream. Coffee can be likened to fuel on the fire of your metabolism allowing it to burn faster and brighter. If you’re not providing wood for it to burn on (energy)— particularly in the form of balanced macronutrients ideal for you (like kindling, logs, and paper) then it will simply burn itself out. You start to experience anxiety with drinking coffee, or over stimulation to the point that you don’t get anything done because you’re overwhelmed.
Cultures that incorporate coffee into daily life like in Italy or Ethiopia are known to pair it with food, providing what’s needed to handle it optimally.