The moment I replaced my coffee addiction with dark chocolate, no sugar, just 100% cocoa, I started feeling better and having flatter belly.
Really, and this is what I found out; the main reason for my big tummy before is excess carbs (from rice, bread, pasta, pizza, etc), and excess sugar (from sugary drinks, cake, donuts, etc).
The moment I surrendered and stop eating rice, bread, and sweets like cake, ice cream, donuts, you name it, I started feeling better and having flatter belly day after day.