HW: High weight, the heaviest weight you've been or the weight you started pro Ana at.
LW: Low weight, the lowest weight you've been at.
GW1: Goal weight one.
GW2: Goal weight two.
UGW: Ultimate goal weight, the weight you want to be at forever. :)
Ana: Anorexia (duh)
Mia: Bulimia (once again, duh)
ED: Eating disorder.
EDNOS: Eating disorder not otherwise specified.