If you lose 2 pounds a week, that is a calorie deficit of 7000 calories/week or 1000 calories/day. I can see that.
If you lose 5 pounds a week, you have a calorie deficit of 17,500 calories/wk or 2500 calories/day.
Seems way too high to me. You would have to work out many hours a day every day to hit that number, yet your body would need recovery days.
Does not seem possible. I realize this is a thumbnail sketch, but what's wrong with this picture?