The last couple of months I've been losing weight and the thing is, I don't want to (actually want to gain weight). I eat like crazy and I work out just as much as I normally do. Only thing different is that my stomach seems to be acting weird now and then. I take protein shakes and even creatin (which is supposed to make you heavier). I've taken protein and creatin since about 3 years now, so that can't really be it. I've lost more than 5 kg in the last 3 months, which is like 10-15 pounds. What could cause this problem? I was thinking I could be lactose intolerant, but why would that start now?