Ummm no it's not. I've owned 8 rats as pets at different times when I was younger. Rats are supposed to eat fruits and veggies and lab blocks are only supposed to supplement. Obviously those dietary needs are not as nesissary if the rat is to be food bc you aren't looking for the longest life possible. Lab blocks can cause tumors in old rats when fed excessively throughout their life. Again for a feeder rat, they are fine and nutritious. But either way fruits and veggies are Not a bad thing health wise for rats.
*MissMishyyy*