The crux of the alli plan is that you have to eat a sensible, low-fat, reduced-calorie diet and get a moderate amount of exercise while taking the capsules.

For those interested in following a diet program or plan, here are the pros and cons of using alli with popular diets - from the very low-fat to the low-carb, high-fat .

As the graph from the Companion Guide inside the alli package shows (click on the image above), you want to avoid diets very high in fat like the Atkins program. Why? You'll get treatment effects like loose stools and have to get to the bathroom very quickly. alli blocks 25 percent of the fat you eat so the more fat you take in, the more fat needs to come out the, er, other end.

By the same token, you want to avoid diets that are very low in fat, like Pritiken, since there's little or no fat to block. 

The good news is that there are many diet programs that work in combination with the alli program.  Commercial weight loss programs like Weight Watchers, Jenny Craig or Nutrisystems all have low-fat reduced calorie options that are compatible with alli.   

This is not an endorsement of any of these diet programs. And they haven't endorsed alli.  Just an explanation.