One should always be aware of the indicators of an eating disorder:
Discuss your concerns with the person before suggesting that they have an eating disorder (i.e. make sure they don’t have another illness such as the flu).
When having the conversation be compassionate and open and encourage them to seek professional help. Also, don’t be surprised if they refuse to talk on your first attempt to talk with them; this is a frightening situation for them to be in.
It is important that you listen without judging. Listen and validate the feelings they have rather than telling them how they should feel in this situation.
Learn everything you can about eating disorders to further help the individual you are concerned about.
For a detailed write up on what to do if you think someone has an eating disorder, visit here.
Source: Central Eating Disorders - NZ www.eatingdisorders.org.nz