I have been taking alli 2-3 times a day for a year now and have never had any treatment effects at all. As long as you stay under 20 grams per meal, you'll be fine. My target is 15 grams, so it's not a problem to stay under 20. You just have to know exactly how many grams of fat you are eating. Don't guess, approximate, estimate, or round off the fat grams or just say to heck with it; that's what can get you into trouble. I measure food in a measuring cup, weigh it on a scale, and count out pieces and have been doing that almost every meal for a year. I also record every calorie and fat gram I eat and calculate my weekly averages. IMO, alli is not for people who can't be precise and consistent.
If I don't know for sure how much fat I am eating, like in a restaurant or at a party, I don't take a pill. Usually in restaurants, I chose something that is low fat and skip the pill, and at parties I eat very, very little or I skip the pill. At home, I have to make an effort to be sure I am eating enough fat for the pill to benefit me.
Eating a lot of fiber can mitigate any treatment effects you might have. I eat a ton of fiber.
If you only need to lose 15 pounds, are you really medically overweight? Is your
BMI in the normal, overweight or obese category? The reason I ask is that alli is meant for people who are overweight or obese and usually that means people who need to lose a lot more weight than 15 pounds. If your weight is normal but you still want to lose 15 pounds, you don't need alli. Some other diet will work better for you.
Good luck. Alli works if you can follow the instructions and stick with it.
Caroline

SW=197/sz 20 (8/22/08)
CW=157/sz 10
GW=150/sz 10=7 more pounds!!!
50 y/o, 5'9"