BCE0044 error

So, my hunger code is supposed to subtract 1 from Hunger every 5 seconds after 300 seconds have passed. But I get BCE0044 and UCE0001 errors. This is my code;

 #pragma strict
 
 var Hunger:float;
 var MaxHunger:float=100;
 var timer:float;
 
 function Start () 
 {
     Hunger=MaxHunger;
 }
 
 function Update () 
 {
     timer+=Time.deltaTime;
     function hungerSub(){
     setTimeout(
     function() {
     if(timer>=300) 
     {
     Hunger-=1.0;
     }
     }, 5000);
     }
 }

And this is the error:

Can anyone help?