I want to lose as much weight at possible by Christmas.I’m on LA weightloss. Alli. Climbing stairs. walking

This is what I am doing:

1. I am on La Weightloss Gold Plan
2. Ordered Alli today (online)
3. Climbing stairs ( approx 240 stairs)
4.Walking for 45 mins

I have two questions:
1. Can i use Alli with La weiht loss diet program?
2. How much do you think i will lose (range)…by December 25th..if i continue following this diet?