What can be done to shed pounds fast for martial arts ?

Not possible: Losing weight fast means losing waster. There is not a good way to safely lose fat weight quickly. Typically 1-2 pounds a week is normal on a good program. If your are heavier, you may lose 3-4 lbs initially per week but you will taper off to 1-2 quickly.

Not fast: Eat healthfully. Try to eat at least 5 servings of vegetables & 4 of fruit per day. Increase nutritional fiber. Avoid refined sugar & junk carbohydrates. Avoid alcohol, sweetened juices, soda & caffeinated beverages. Aim for 7.5 to 8 hrs of sleep / night. Hydrate w at least 64 oz of water / day. Calories burned must > calories consumed. Do both cardio & weight training.