I just wanted to point out that it's perfectly normal to be body-conscious or have less-than-healthy eating habits. Many people find eating to be a stress relieving act, hence the term "comfort foods".
Looking at our world today, processed junk food is abundant and can be prepared quickly. Exercise does not happen naturally as many people have sedentary jobs (and many people must work overtime in order to make ends meet). All while simultaneously, media is bombarding us with the "ideal" body image. This is causing many people to develop a negative relationship with food. Much more contributes to this, but I'm sure you are all already aware of what's going on. The important thing to note is that these are external forces working on us, making it more difficult than before to maintain a healthy level of nutrition.
EDs are actually psychological disorders that go beyond the occasional feelings of guilt or irregular patterns of eating. They can quickly become crippling or even fatal, and the person may feel complete lack of control over his/her impulses. In many cases, patients describe that the disorder no longer becomes about food and the fear of becoming overweight, but more so about having complete control over a single aspect of their lives. Like many mental disorders, however, EDs are widely misunderstood.
It is important to be observant- after all, your kind intervention may save somebody. However, please do not assume somebody suffers from an ED without reasonable cause. Thin people may simply be thin. People can have different eating habits due to disorders, certain medications, religious practices, allergies, etc.
I experienced a phase several years ago and lost about 30 lbs in a month, making me underweight. It's strange for me to recall this, but there was a time when the mere thought of keeping food down made me feel horrible. I'm lucky to say that I grew out of this. As I matured, the habits dwindled and it no longer made sense to me anymore. I'm unaffected by this today, but I recognize that the option to slip back into old practices may always be there. When I began working, I think it actually helped me. Encouraging patients and educating family members about positive health made me want to take my own advice. It was as if I didn't want it badly enough for myself, but wanting it for other people opened my eyes to it. For those of you who are working and affected by an ED, try to find motivation rather than triggers. You must set a great example- you are a beacon of health to people! Engage with groups who will keep you accountable to your goals (friends who expect you in the cafeteria at lunchtime, etc.) And if you care for the people who come through your doors, remember that you must take care of yourself in order to take care of them.