In order for you to achieve your goal, you'll need to burn 2000 calories more daily than than you consume. You'll end up sick from ketones levels that are way too high, and this demise of your health will not be prudent. However, if you can maintain a tremendous amount of aerobic activity (approximately 2 hours non-stop) you may burn up to 1500 calories, along with a basal metabolic rate of an additional 1700 calories, for a total of 3200 calories max burned per day. Given the hypothetic ability to maintain that level of activity, you could reach the net burning of 2000 calories per day by limiting carbohydrate intake to 1200 calories per day. ( 400 calories per meal, x 3). This would then equal 4 lbs weight loss per week.. This formula is likely too radical to maintain for more than 2-3 weeks.