The Daily Mail might not be a great source of any accurate information, however, over the years I have read of the benefits of cocoa. I had a quick google and found this link interesting:
https://www.healthline.com/nutrition/cocoa-powder-nutrition-benefits#section10. I'm sure there are other links worth looking at for more information.
I also had a quick check of how much carb is in the stuff we could buy in the supermarket. Tesco own brand has 11 gms carb per 100 gms or 0.4 gms per serving. Other brands seem about the same although I noticed that Holland and Barret organic cocoa was twice that amount.