The Engine That Burns Fatty Fuel
Muscle tissue is the engine which burns the fuel (calories). Losing fat requires the engine to burn more calories than you ingest, so it's forced to tap into stored calories (fat). The more muscle you carry, the more calories you burn.
The Carb Dilemma
From two decades of competing I've learned that eating too many carbs makes it darn near impossible to get shredded. But at the same time, elimination of carbs makes it difficult to train with the intensity and stamina necessary to maintain or gain muscle.
So the best way to lose fat is to eliminate starchy carbs in favor of lean protein and healthy fats (coconut, olive, avocado, etc.) with the exception of the workout window.
The workout window includes 30 minutes prior to your first working set until the completion of your workout. Depending on the length of your workout, this should amount to about 80-150 grams of carbs in the form of highly branched cyclic dextrin. I use Plazma™.
These carbs will provide the required material to train with intensity, blunt a prolonged catabolic spike in cortisol, and jumpstart recovery so that you build and maintain the engine (muscle mass). As for the rest of the day, limit carbs to fibrous vegetables.