Hi Kev
I wouldn't be too disappointed, most of the weight loss the first week is water - it's the weeks after you are burning up fat, so the 6lbs is 6lbs of fat and no water! Cheese is low carb, but high fat, so it won't effect your ketosis, but if you kept doing it, it would slow your weight loss. 6lbs is very good - it's almost half a stone! Well done!