THE ENCYCLOPEDIA GALACTICA
UNIVERSAL FOOD GROUPS
There are five food groups which are universal in that they are known and used by all known sentient organic creatures. They are theobromine (the active constituent of terrestrial chocolate), caffeine, nicotine, alcohol and Swedish meatballs.
There is a school of thought that the number 42 - the answer to life, the universe, and everything - is actually the number on the take away menu for Swedish meatballs, thus making Swedish meatballs the answer to life, etc, etc.
In passing, it should be noted that the micro-fusion packs of non-organic life - robots, etc - are also optimised for the mass-energy conversion of meatballs, regardless of which race the robots originated with.
All beings should consume a minimum of 18 units (for some definition of unit) of each of the five groups each day in order to stay mentally alert and physically fit. In some cases (for instance silicon-based life forms) pizza may be substituted for Swedish meatballs.