Is there a way that i can lose 100 pounds before christmas is there a safe way that i can do that.?

Unfortunately no: Starvation diets cause substantial reduction of your metabolic rate - 1 lb a week is a reasonable goal - weigh frequently (daily) - increase your exercise - decrease carbs - go to bed slightly hungry every night -.

Unrealistic.: We recommend a loss of weight of no more than two pounds per week, so in order to lose 100 pounds by Christmas you would have had to start last Christmas. So unfortunately there is no safe way to lose that much weight in a short amount of time.