Premium foods are usually different than many other foods in 4 key areas. First is fixed formulas, that is, formulas that are not varied depending on the cost and availability of ingredients. Second they usually use high quality ingredients. Third they are usually highly digestible meaning the pet utilizes more food and less is wasted. Lastly, most premium foods offer life stage nutrition, that is separate formulas for growth, adult maintenance, weight loss and senior dogs.
Life stages refers to the various developmental stages of an animals life.
For dogs it means puppy, adult, senior and for some dogs a lower calorie diet for inactive or overweight pets. An adult formula contains moderate amounts of these nutrients. Senior diets generally contain less fat and fewer calories than adult diets but are often fortified with extra vitamins and minerals. Lastly diets for overweight or inactive pets contain more fiber and less fat and calories than the adult diet. Some people leave food out all day long for their dog.