The issue with the bars is that they have sugar alcohols in them, along with other artificial sweeteners. The shakes also have artificial sweeteners, but the flavors I have at home have no sugar alcohols.
Not only can the SAs create some digestive "disturbances,"
but some individuals are sensitive to the SAs, as far as weight loss is concerned.
There's a vast difference between some of the Atkins products in terms of how many SAs are in them....as examples: The Atkins Endulge Peanut Butter Cups have 11 g. SA in the 2 cups, the Nutty Fudge Brownie has 10 g. SA but the Peanut Caramel Cluster Bar has just 4g. SA.