Do not attack
them
Sit the person down and have a talk with them. Listen with understanding. Do not be judgmental. Tell them all you have learned about bulimia. Tell them you are being concerned about their health, their eating habits. Attacking them would make them go on the defense and you would never be able to proceed from there on.
Give your
support
Tell that them you are there to give them support. You could always be available for them. Tell them that if they do not want to discuss the matter, it’s okay but you are always willing to help them should they change their mind. You could accompany them to a counselor or a physician to get themselves checked.
Find social
groups
You could also find a social group for your friend with other sufferers of bulimia. Together they would be able to help each other through it. These social groups will create a safe environment for your friend to feel comfortable in.
Be there for
them
Lastly, be kind and understanding. Know your limits. You can’t give them the professional help they need. Just be prepared to give them the moral support they need. Fighting bulimia may be a lifelong battle and they need all the help they can get. So be there for them!