How can you disagree with a physiological fact? I didn't just pull this out of my ass!
Well, what you are saying could be debated extensively. However, yes insulin production can go up since ephedrine can cause some insulin resistance. So when eating over maintenance, ie bulking, it *might* be a bad idea. What you are not telling here is that the reason the best fat burners, including GH (!), clen, etc, are such good fat burners is largely due to the insulin resistance they cause. One reason is that insulin resistance in fat cells make them release fat easier. In a deficit this means you are burning fat for fuel.
GH can, and will in high doses, INCREASE insulin production! This is fact. When was the last time you heard of someone getting fatter from GH?!! High dose GH use can cause such severe insulin resistance and high BG that some have to use supplemental insulin to keep BG down.
So, I would say you are off in saying ephedrine makes you fat. It *might* be a bad idea health wise to use tons of ephedrine and eat huge amounts of carbs, though.