Puppies need to eat a LOT more because they are still growing like crazy. By a year old the dog is generally considered an adult. While she will probably still grow some more, it isn't nearly as much as between puppy and a year old.
While we are talking about food, please make sure you are feeding a good quality (expensive) food. If you are feeding a cheap food you are getting what you paid for. Cheap foods don't have much nutritious value to them, so dogs eat a lot more of them to get the nutrients they need, and more food going in means more poop coming out. Cheap foods are like eating fast food your entire life, its just not healthy. Expensive foods have much more nutrition and are better for your animal in the long run. You need to feed much less of the good food because it is much more nutritious, and less food means the bag lasts longer and there is less poop. Cheap foods have little actual meat in them and contain more corn and rice and other filler foods, while expensive foods contain a lot more meat, which is what dogs need more of.
If you already knew that, sorry, but I thought I would inform you since we are on the subject of feeding.