I think it has to do with the fact that hot cereals tend to have a lot more fiber, so consequently fewer usable carbs. That may have something to do with it, or maybe there is HFCS in there too. That may do it. It's also pretty easy to overdo the portion size when it comes to a yummy cold cereal.
Dxd T1 1966, 2001 dialysis, 2002 kidney transplant, 2003 insulin pump, 2008 pancreas transplant