I'm just wondering at what age you typically start to reduce a puppy's food intake? I understand that puppies need to eat more than adult dogs, so I'm just wondering at what age you start to reduce and typically (I understand every dog is different) how much do you feed?

Currently, I'm feeding Casey (an 8-month Cardigan) about 2 heaping cups of kibble a day (so about 2 1/4 cups) and then she gets a mid-day snack (usually a denta-stik or some chicken jerky). On top of that, she might get some other misc. treats like some cut up hot dogs for training or I might throw some fruit/veg in with her kibble. In total she probably gets around 3 cups of food a day.

At what age do people typically start to reduce this amount?