Hi Msbtr,
What made you decide to go that low in calories and fat? Alli is meant to be used with a low calorie diet that has 30% of it's calories from fat. Taking it when you only consume 10 grams of fat per day is unhealthy for your body. If you are not willing to eat more fat you should definitely not take alli.
As for your calories, why did you choose 1000? I don't know how much weight you have to lose so I can't say how many calories you need. Go to http://www.freedieting.com/tools/calorie_calculator.htm to calculate your maintenance needs. From there, subtract 500 to 1000 calories per day for 1 to 2 lb weight loss per week. If you are counting calories and still not losing at the number that you calculated, I recommend seeing your physician to rule out any medical reasons for this.
Good luck,
Betty Kovacs, MS, RD