Broadly speaking, following a balanced diet which includes fruits, vegetables, meat, fish, etc. is the most advisable. Some specialists recommend including dried fruits and nuts, as well as gelatin, which is a protein-rich food. On the other hand, eating ham is unadvisable, as it increases the risk of having toxoplasmosis in case you're pregnant.
As for what to drink, alcohol and fizzy drinks should be avoided at all costs. Staying hydrated is a must, so pay attention to drinking plenty of water. Include orange juice and isotonic drinks as well, given their high content in mineral salts.