How to know if you have an eating disorder ?

Document them: Keep a diet diary and show your doctor after you have more than two weeks recorded. Record what foods and how much you ate as well as the time and date. Also record behavior such as vomiting, skipping meals or taking laxatives.

Worth exploring!: I say if you think you might have an eating disorder, that's reason enough to visit with a specialist/psychologist and explore your eating behavior and related concerns; if not a full fledge disorder, eating does get disturbed, at times, as a symptom or an indicator of other psychological dynamics or issues worth addressing and resolving. Exploring can do no harm, and likely lots of good!