Should I Switch Dog Foods & what should I switch to?

Question
Hi Labman,

My family just recently adopted a two year old female Labrador Retriever who is planned to come home to us in October. She is slightly overweight which I am concerned about because of labs tend to have bad hips, but they are currently monitoring her weight. Right now, she is on the Royal Canin Labrador Retriever 30 food and I am concerned about the high levels of corn and grains. The one thing I like about it is that it contains glucosamine, which I heard is good for their joints. I was considering switching to Orijen dog food once I get her more active. She does get daily exercise but not as much as I like and I am planning to slowly get her more active and then switch her, but I have heard that the high protein levels in Orijen dog food is bad for the dogs kidneys and livers and is only meant for agility dogs, is this true? I was also told about Acana another brand made by the same company as Orijen, and I was also recommended Fromm. What do you think I should do? Besides being a little over weight, our lab is quite healthy and we have no other concerns. Do you think we should switch from Royal Canin or just stick with it, or do you think we should switch and what do you recommend we switch to?

Thanks,
Violet

P.S. I was also recommended "Petritionals" for her hips and joints as I plan to do Frisbee with her. Do  you think it's worth it? ( http://petritionals.com/ ). Thanks, if now, what do you recommend for her hips.

Answer
The best thing for her hips is to get her weight under control as you plan.  Frankly I think 99% of what you read about dog food is nonsense with absolutely no scientific support.  It is true the more corn and other grain in a food, the more you have to feed and the larger and softer the stools.  However, that has absolutely no effect on the health of the dog.  All modern dog foods are formulated to contain the nutrients dogs are known to need.  The excess protein some contain is burned for energy or excreted.  In some cases, the advertised high protein levels contain a poor balance of amino acids.  Dogs don't need meat or protein, they need specific amounts of specific amino acids.  They will do fine on any food that provides enough of each one no matter its source.  

Much of what you read about dog food is from somebody selling something or true believers that have bought their marketing hype.  There is also a lot of generalizing from too few examples.  There are absolutely no controlled studies available to the public comparing different diets.  Most of the good scientific data isn't available for free on the internet.  Much of what I have read is wrong and reflects dishonesty or ignorance.  

If she is doing well on the Royal Canin and you don't mind paying its price, I would stick to it.  There is no rational reason to switch to the Orijen, Acana, or Fromm.  I have seen reports of dogs doing poorly on all 4.  Most dogs will thrive on most foods, but no one food is right for all dogs.  Stick to what is working.  I have seen many times people switch to a ''better food'' and the dog does poorly on it.  

The Petritionals is hype too.