Olah,
Eat what you like... just not in abundance... and avoid alcohol, greasy food and caffeine products.
Usually I’ll eat something like a banana and other fruits (nanas are good cause they contain potassium and keep you from getting leg cramps... they also can settle your stomach.) Then I throw in something like my favorite crackers (chees or peanut butter) and have some liquids... either water, lemonade or a gatorade type drink... these are the best things for hydration...
Hope that helps... Happy Diving...