I was able to switch my 2 year old corn in one feeding but Regis is not even considering it. I have been trying f/t for 3 months and he would not touch them. Over those 3 months he had lost 40g. I think that's too much. I will keep trying to sneak the frozen ones in but I will continue to feed him live in the meantime. I don't want him losing any more weight or getting stressed over this. He may or may not be able to change his ways. Who knows?