What is going on with my son?

So my son is just over a year old and up until about a week ago he was eating and drinking loads but this week he seems to have gone off nearly everything he normally likes or doesn't finish something he would normally finish. He is pooing more than usual, but hasn't been ill or sick recently and his hands and feet she always cold even when they are covered up.

He whines alot more too which is unusual. He isn’t my first I have a teenager so little out of sorts here, any help or advice would be great TIA