From a TCM perspective, raw foods will further weaken spleen energy and should be avoided. Foods should be at least slightly cooked (even salads) to start the breakdown so that they are easier to digest. It is also very important to stay away from sweets. While 'sweet' is the flavor that is associated with the spleen and helps nourish it, in TCM they are referring to the natural sweetness that is found in such foods as yams, gourds, squashes, root vegetables, sweet rice etc. and not what we commonly consider as sweet in the West. Even fruit can be detrimental if the spleen energy is already weakened; being too sweet and also usually eaten raw. And beef can be very beneficial for spleen deficiency. The spleen is also the earth element and associated with the color yellow so you might think of planting some daffodils!
Here are a few links which provide some information on the spleen including herbs and diet. Acupuncture, exercise and avoiding excessive mental activity (ungrounding) and managing stress and worry are also indicated for spleen conditions.
(Although the last link article is written by a vet, it still provides a good introduction to a TCM diet and includes foods suggested to treat various conditions)