What dog food is best for my dog?

Question
I have a German Shepherd/Belgian Malinios Mix. I am having trouble deciding which dog food is best for him. He is only 5 yrs old and weighs about 105 lbs. He is a big boy. I want him too live a long and healthy life. Because Shepherds suffer from hip displacia, I want to make sure I am feeding him the right food. I have been feeding him Nutro Max for large Breed Adults. And he does pretty well on it. However,My husband bought him Purina Beniful last week, and he seems to have much much more energy. Is one dog food better for his breed than the other?

Answer
If there is any research comparing how dogs do on different diets, it isn't available to the general public.  The internet is full of strong opinions based on marketing hype, junk science, anecdotes, misinformation, lies, ignorance, bias, world view, and everything else except facts and logic.  An example of the thinking is that P&G recently bought out one of the small, premium brands.  Most of the rating sites immediately lowered their rating even though nothing changed but the ownership.  None of the rating systems are based on the health of dogs eating the food.  

I have no evidence that there is any real problem with Beniful.  Nor do those bashing it.  I find its marketing hype a little thick, it does have artificial coloring, the increased energy may come from sugar or other sweetner, and of course, it is a product of Nestle.  I don't see any of that as not being good for your dog.  If you are happy with the increased energy, I would continue feeding it.  Dogs nutritional needs are well known and can be met in a wide variety of ways.  All the modern dog foods are formulated to contain enough of everything dogs are known to need.  As long as you watch his weight, he should do fine on Beniful.  See http://www.longliveyourdog.com/twoplus/RateYourDog.aspx  Many Shepherds refuse to eat more than they need.  

There is little you can do about hip dysplasia now.  It is mostly genetic although diet is a factor in the first year, excess calcium, overweight, and fast growth can lead to problems too.  You might start adding glucosamine to his diet in a few years.  Hip dysplasia develops early, but a young dog may hide the symptoms through muscle tone except in severe cases.