If it is a preoccupation with loosing weight, it can be called anorexia. Some people loose so much that they look like walking skeleton. Many don't seem to notice how bad it is.
That would depend on what your eating disorder is, if it is that you are prone to overeating, it is going to be difficult to lose weight, on the other hand, if you have a eating disorder like anorexia or bulimia, you will lose weight.
Example sentence - We were concerned about his weight and whether or not he had an eating disorder.
You can lose or gain weight. An eating disorder could be you don't eat at all or you eat too much, such as seeking food for comfort.
Fear of eating and gaining weight is a common sign / symptom of an eating disroder.
Anorexia Nervosa
An eating disorder can lead to many severe health problems. With anorexia you may loose weight but not in a good or healthy way.
obsessive compulsive over eating Binge-eating disorder
The eating disorder known as EDNOS (Eating Disorder Not Otherwise Specified) is usually diagnosed to someone that is struggling from eating disorder behaviors but does not have the symptoms of bulimia or anorexia. Some symptoms of EDNOS include constant concern about food and weight, behaviors such as restricting eating or that compensate for eating (like exercising or purging).
Anorexia, bulimia, ednos +
Binge eating disorder (BED) is by far the most prevalent eating disorder, affecting nearly 3% of the general public and 30% of obese individuals seeking weight loss.
a eating disorder is really unhealthy for the body and once youve gain so much weight its gonna get hard to lose a few pounds