Few topics seem to be as controversial as what the best brands of food for rats are, which is somewhat ironic given that they are omnivores who can and will eat almost anything we do! 

Always use a good commercial laboratory block as the staple diet. Unfortunately, it sometimes seems that the better the food, the harder it is to obtain. I use Harlan TekLad's 2016 Rodent Diet for the adults, and 2018 for the youngsters. Unfortunately, the food is not carried through any normal distribution channels, so you either have to live close enough to the warehouse in Madison Wisconsin to pick it up yourself, or find one of the small operators who will repackage and sell it. See the links page for more details.

In addition to the lab block, you should supplement their diet several times a week with small quantities of seed mixes, yogurt, vegetables, breads, eggs, and grains. Do not give rats peanut butter or other "sticky" foods because they have no gag reflex, and can potentially choke on it. (rare, but it happens). If possible, make a game of feeding; rats can fish the vegetables out of a container of shallow water, or find other foods in a "dig box." It's a good idea to have a ceramic or heavy duty glass dish to place foods in, especially the seeds and grains, but be prepared that your rats will probably stash their food in various parts of the cage. 

Most commercial diets contain enough salt, but it's not a bad idea to place a salt lick in the cage. If nothing else, they will use it as a chew toy. For some reason, my rats almost universally prefer the apple-flavored ones. Unless your rat has special dietary needs, you shouldn't need to use supplemental vitamins.

Rats require large amounts of fresh water every day. Unlike desert rodents such as hamsters and gerbils, they drink large amounts. If possible, use a glass water bottle to help prevent chewing. Otherwise, be sure to use a metal guard on the bottle holder or mount the bottle to the outside of the cage.