At least for those that consume instant coffee that they prepare themselves, more important than talking in terms of cups is to mention that 1 gr of instant coffee contains 32 mg caffeine (that’s what I found, don’t trust me, do your own research; besides that, it may vary with the type of coffee beans etc), and that 1 rounded teaspoon of instant coffee means 1.8 grams of coffee (so, 1 rounded teaspoon of instant coffee = 57 mg caffeine, 7 rounded teaspoons will make the upper daily limit, 400 mg of caffeine).
To support this argument, consider this. A recent in-depth research done in Turkey last year revealed an inverse relationship between consumption of coffee and blood levels of all liver enzymes. Conventionally, increased levels of liver enzymes reflect damage and inflammation to the liver. Simply, the more coffee drank, the lesser their enzyme levels.
Coconut milk is the perfect add-in if you’re lactose intolerant, cutting out dairy for dietary purposes (i.e. the Paleo diet), or just want a low-calorie milk substitute. Of course coconut milk adds a light coconut flavor to coffee and lightens up your brew, but it’s also closest in texture to whole milk. You can add vanilla extract to coconut milk to create a homemade, lower calorie creamer. Just be careful and use coconut milk sparingly as it still contains a fair amount of fat.