You're saying this based on what exactly? I've heard that coffee/caffeine is most effective at boosting sharpness when your stomach is not empty. (I'm under the impression now that there is more than one reason why coffee after a meal is the recommended way to take it, and not understanding how whether you take it with milk plays into it... could you elaborate?)
Not the parent poster, but I understood this as "black coffee has almost zero calories". This was the only restriction I explained in my post. This is not about boosting the effectiveness of coffee, but simply cutting out all calories between meals (except possibly for neglectible amounts as in tea or coffee).
Ah, thanks for the clarification. My understanding about the effects of caffeine is not based on anything other than hear-say from people who seemed to have done their research better than I have, but from what I did hear, caffeine on an empty stomach may have opposite the intended effects, making you actually more confused instead of boosting focus.
Anecdotally after hearing this myself, I have tried to make it a point to take coffee less often when on an empty stomach, and it does seem to help with focus-depletion.
