Yeah probably DNP
Obviously diet and cardio.
Focus on the type of cardio you are doing. An hour of low-intensity cardio every day is often times not the best way to lose fat, although for many people its been the conventional norm.
Try wingate sprints, or a modified form on a resistance bike, for 4 minutes. Watch them on YouTube for a few minutes to get an idea of how to do it. They put your cells in such a depleted energy state that it forces them to rapidly switch to fat burning, increase nuclei, etc. I don't have the study on hand but there has been some pretty good research on them.