How do you know that you have a eating disorder?

you didn't say which type of disorder, not eating food or eating too much, so i will assume you mean not eating.
Firstly you will make any excuse not to eat, you will start lying about how much you eat, you will hide food to make people think you have eaten well, you may also try different ways of getting rid of the small amount of food you have eaten, by making yourself sick or taking laxatives. You will look in the mirror and think you are fat when you are probably in reality very thin.
If not treated by professional help then your body becomes run down through lack of nutrients, you get lethargic and eventually develop a fear of food, you shake and break out in a sweat when you see large amounts in front of you. You will also make excuses not to attend functions that serve food.... parties, family get togethers etc.
If you see all the above in you, or even some of the above then please talk to your Doctor, its more common than you think, and they can offer you proper help. Source(s): My wife was an Anorexic for 6 years.

They point & say you're Fat
or they point at the Skeleton.

Either one's bad for you!
If you are eating on a binge and purging or if you are trying to diet constantly and you already weigh 80 lbs. and not eatting at all because you are a fat blimp at 80lbs (so your mind tells you this)
(Just a note that they might take this question off--because I believe it violates the Community Guidelines).

If a person who is normal in size, or even thinner than normal, but sees themselves as fat in the mirror, that is a warning sign.

There is also an eating disorder where people eat too much--and don't care about their health or shape.
If you skip meals even though you're really hungry, or make yourself sick after eating, or cannot stop yourself eating even though you feel really sick afterwards. That just about covers it.
well you can tell. or u can go to your doctor and ask if you r. but if u dont want to than if u have a eating disorder you eat to little or you puke it all out when your done, or you eat a lot and you never can be full.