Going into it I knew my vets were well educated and intelligent people. One was out of school within the last few years and the other has been working for quite some time in her career. This clinic had the best of both worlds, experience and new ideas.
Also going into my internship I knew vets don't learn much nutrition. It is required as a prerequisite to vet school for only some programs. I know the newer vet did not have to take nutrition classes to graduate, I don't believe the other did either (her school now requires it).
(Note: Much of the same problems occur in the medical industry I am just less familiar with details.)
In short, vets don't know nutrition.
Today, I was afraid to ask my vet about my cats' food amount. One is ideal weight and eats mainly wet food and the other is over weight and eats mainly dry. Being I have my own pet food company calculating the calorie content of each food pet a cup was a breeze. I figured my brand of wet was 1/3 the calories of my dry. Solution was to make the fat cat eat more wet food. Could the average, or even above average pet owner do this? Could my vet do this? Could yours?
The problem was I don't know how many calories a cat needs. Lets just say I was afraid to ask.
Nutrition information exists. It is well researched. There are scientific articles, journals college classes all for animal nutrition. Crustacean nutrition alone has a scientific book of 600 some pages. There is not any information at all on crustacean medicine.
So in this vacuum of knowledge of general practices what do the big names in pet food do? Take advantage! The reference anatomy book designed for a crude reference for vets to explain to patients is by Hill's (aka science diet). The obesity charts posted in the rooms are by Nestle (Purina). Each page of the anatomy book suggests a diet for pets with different conditions to go on. The wall chart advertises low calorie and high calorie foods. The real medical texts are produced by real DVMs and are backed by real research, but what the owner sees is a connection between science, nutrition and poor quality food.
An apple a day will keep the doctor away, but they will let you eat as you please.