Glad you brought it up...

While I don't think that a fast with just shakes would be best, given the benefit of fiber in your diet, I do recommend the shakes. I actually do not use the Atkins variety, but use "On's Double Rich Chocolate" instantized whey protein blended with heavy cream, ice and a shot of sugar free Kahlua syrup.

Tastes just like a Mudslide! And with approximately 3g of carbs and 23g of protein, sheesh! How do you go wrong?