If soy milk is out of the question it *could* be sugar. Try cutting out 100% of the sugar (including milk), corn syrup, dextrose (aside from fresh fruit) from your diet for 3 days.

I'm not one to check out nutrient facts on the back of things, which is probably not a good thing. I figure the obvious, grease bad, fruit good. I definitely need a more healthy eating plan. I just suck at sticking to things like that.