The nutritional requirements for a puppy vary throughout the first year of life. It is very important that a puppy receives the best nutrition possible during this time and that the nutrition takes into account the size of breed especially as the larger the breed the lower the requirement for calcium as excess can lead to developmental problems with the bones.
The maximum nutrition is usually required at around 6 months of age and gradually reduces thereafter. Normally the feeding guide is based on the current weight and the amount will therefore increase as the puppy gains weight with age. For the smaller dogs (up to around 10Kg adult breed weight) you can normally continue feeding the puppy food designed for smaller breeds for life but at 50% of the amount suggested for the puppy stage from around 6 months of age.