I am 4' 10" tall. Is a 1000 calorie diet too small of an intake?

I am overweight and have been trying to lose weight and get back into shape. I weigh 140 lbs. I have been doing a cardio workout about 30 mins per day and do pilates for about 20 mins per day, the rest of the day I have a sedentary job. I know that normally a 1000 calorie diet would be too small because your body reacts by slowing down metabolism, but does anyone think that would apply to me because I am so short?