but this can be one of the most difficult steps for someone suffering from an eating disorder, so try to encourage them to seek help or offer to go along with them.
keep trying to include them – they may not want to go out or join in with activities, but despite this, keep trying to talk to them and ask them along, just like before. even if they don't join in, they will still like to be asked. it will make them feel valued as a person.
try to build up their self-esteem , perhaps by telling them what a great person they are and how much you appreciate having them 