I've been told to start integrating liquid protien into my diet to prepare for the pre-op liquid diet. Is there a difference between Slim fast Optima, High protien and the regular meal replacement shakes (beside the prices?)

I use Slimfast low carb. It has less carbs and 20 g of protein. I personally like the vanilla.

Most of the other shakes you can get at gnc or a health food store have more protein in them (usually at least 30 g)