flk:
I have gained about a stone and a half since starting. While stuffings help me gain body fat, I have noticed it is only when regularly drinking heavy cream shakes (50/50 double cream to strawberry or chocomilk) that the scale really starts to fly up. Of course, this is mostly down to water weight, but it quickly settles as fat. I think with 300ml you will start to see results from experience. Go easy though, it is easy to overdo it and I have been right on the edge a couple of times after downing more than two pints of shake. A blender would help you mix up your options a bit as it can get quite repetitive, else just add it to meals etc
Heavy cream and chocolate milk sounds tasty lol