..a friend who works in a hospital told me that slimfast is the same as the stuff they give the elderly to build them up before ops... the difference being that they get meals too...besides it's a complete rip off...
Thirst is often misinterpreted as hunger. Slim Fast only replaces meals and so would obviously help lose weight due to the decrease in the amount of food you are eating. Try more fluids when you are hungry and see where that gets you.