There are several different traditions concerning food in Judaism.
The first has to do with ritual purity. Certain types of food (for example, pork and shellfish) are considered unclean and completely prohibited. The kosher dietary rules followed by orthodox Jews forbid mixing of dairy and meat, so that you could not saute meat in butter. It is even forbidden to use the same plates for both meat and dairy. For example, if you have ever served a piece of cheese on a plate, you cannot serve chicken at a later date on that plate.
There are four fixed days of fasting in Judaism, and additional days on which partial or total fasts are common.
Several Jewish religious festivals such as Passover and Sukkot have food components, i.e. traditional foods consumed or prohibited.