+1 on everything Fuzz posted. Vet food can be a scam, I don't think all vets promote particular food or intentionally deceive clients. There are big corporations at play here with predictable results.
Quote for the following link:
"And part of the problem, as a Mail investigation can reveal, is that much of the veterinary industry is inextricably linked to the pet-food manufacturers.
Research into pet food is carried out by the pet-food companies but, more surprisingly, the training of vets at some universities is also funded by pet-food manufacturers.
Crucially, lectures on nutrition at a number of vet schools, and for veterinary nurses at individual practices, are also often paid for - and even taught - by these huge corporations, giving them the ideal platform to promote their products."
http://www.dailymail.co.uk/news/arti...-vet-rich.html
It is best that you do you own research and draw your own conclusions about which food to buy for your kitten.