You would call them a sports addict.
You call them a nymphomaniacs.
Obsessed.
I would call them a "Fanatic" or "Super Fan"
== ==
a workaholic
cheesaholic
A wordaholic.
alcohalic
One thing that you can call a person that is addicted to computer programming is a computer nerd. A computer nerd is always on the computer.
a veggie holic
RICH