Calling many methods of many objects many times per second

I have a structure like that

  abstract Class Entity {
    //some variables... 
    //some methods ...
    public abstract void render(Graphics g);
    }

Thats the parent ..Now I have 3 children..

Class A extends Entity{}
Class B extends Entity{}
Class C extends Entity{} 

Every class has some different stuff do render .One is for example drawing yellow circle , second green text and the third is displaying image.

But ... there is a thing.

Class A have List<B>... 
Class B have List<C>... 

One Entity has for example 10 Bs ... and each B has 20 Cs ... So now .. I have a render method that renders 60x per second.. And I have to call every render method from every object.

So I have something like this

for(A a : listOfAs){
   for(B b : listOfBs){
      for(C c : listOfCs){
         c.render(g);
      }b.render(g);
   }a.render(g);
}

Now if you imagine I have much more objects like that and I call this method 60x per second ... I find this really ...really bad practice.. I don't know how to solve this better or so... I don't think that this for each loop is actually the best solution or not. Anyone any ideas ?

I was thinking about implementing the child like that :

Entity x = new A(); ... 
Entity y = new B(); ... 

and so but some of the classes have other methods that have to be looped like that and I cannot call them from parent.

For the render method ... Just stick to the fact that you have to loop something many times in a short period of time for a long time.

I cannot progress through this ... I got stuck here for a long time and I am not sure how to solve this.

via Chebli Mohamed