Plain coffee's aren't fattening, they actually have only about 5 calorie's per cup!
What can make a coffee unhealthy tho, and all those coffee based drink's is the added sugar's/ creamer's/ etc Try adding either TBSP honey (recommended), or 2TSP of an artificial
sweetener (Splenda/ Sugar Twin/ Sweet and Low/ etc ..) with either
skimmed milk's/ 1% milk's or a 2% milk- 1-2TBSP.
Optional additional TBSP cinnamon/ nutmeg/ vanilla or dark cacao powder or extract from another spice such as pumpkin.