Here how this works-
The recommended weight loss per week 1 - 2 pounds
Average calorie deficit needed to lose 1 pound = 3500 cal
If you are to break 3500 by 7 , it is going to work out 500 calories a day.
So if you are on 500 calorie deficit perday you will lose 1 pound a week
1000 calories deficit will help you lose 2 pounds a week.
If you are claiming your BMR is 3140, then if you want o creat a caloire deficit of 1000
then you can do this in 3 ways.
1.you can decrease your calorie intake by 1000 caloires which will leave you with 2120 cal.(this is assuming no exercsie)
2.you consume 312=40 caloreis but you burn off 1000 calories with exercsie.
3.most effective option at that you can decrease your calore intake and still do exercise.
But this will result in rapid weight loss which is not recommended at all.
So to asnwer your question - "Say a 2000 calorie diet and burning 1000 calories from exercise" will create a calorie deficit of more than 2
http://www.medhelp.org/posts/show/661395#000 cals. which will result in 4 pounds a week of weight loss - NOT HEALTHY!