Help my sister is Bulimic ?

I have grown up in a house where my sister was anorexic turn bulimic, this is a horrid situation to live in and impacts the family as much or if not more than the bulimic. I believe that they like the taste of the food, but they tell themselves that they will get fat and they have to purge. As for how many times a day they would purge, I guess that depends on the day of the week. For example if they eat food they feel they are allowed to eat and wont make them fat they may not purge, or they may skip meals and there is no need to purge. My sister used to purge after binge eating junk foods, and almost after every meal that we had as a family because she did like the portion she was given or the type of food and my father made told her to eat it. Whilst it is up to the person to seek help and try and break the cycle I believe it is made better by letting the bulimic choose their portion of food and try talk to them about what they would like to eat for lunch or dinner that night. Also if they binge eat, it can be helped by limiting access to junky foods and take away that temptation in the cupboard. Do not force a bulimic to hold down their food or eat food they dont want to, this can make their selfesteem lower and make the cycle worse. It is ultimately their choice to break this cycle and the best thing to do is try talk about it with them.