Dogs have no dietary requirement for carbohydrates. They cannot metabolise it as we do. They get their energy from fats, which is why it is important not to feed a totally lean meat diet to them. Are they sleepy or just more contented?Perhaps they are less hyper because of the lack of additives. Puppies also go through growth spurts (think children for a mo -although analogies between dogs and children are not always appropriate I think in this case it is), where they use more energy, need more food and will spend more time resting.