Spiking insulin puts your body into "put all of this fuel in long term storage" mode

Which means fewer calories out, so it's still "calories in calories out". And eating a steak and doing some push-ups builds muscle and means more calories out, so it's still "calories in calories out."

It's kind of like how people can argue whether planes stay up in the air because they have lower pressure above the wings or because they exert a downward force on surrounding air. It doesn't really matter because either way the equations have to balance.