If this was just a rat discussion then I would say what a rat eats does effect it's health. If you feed a poor quality diet it can hurt therat, if you feed high quality then longevity comes into play. Remember BPs in the wild eat anything and everything the appropriate size. What they eat isnt always healthy. You sound like you are feeding your rats a good quality diet. Just remember not to go overboard and make them little fatties. They will pig out on seeds lol.