Is body dysmorphic disorder a form of an eating disorder?

If so how do you distinguish bdd from other ed's?

It would be classed as a psychiatric illness.  Body dysmorphia does not always have a food component. 

Body dysmorphic disorder (BDD) typically falls under the category of Obsessive Compulsive Disorder. It usually involves dissatisfaction with a specific part of the body and/or feeling that part of your body seems disfigured, disproportionate, flawed, etc. It usually involves having intrusive thoughts about that part of the body and often involves frequent checking that part of the body or sometimes doing something to "fix" that part of the body.  Here's a description from the Mayo Clinic and a link:

http://www.mayoclinic.com/health/body-dysmorp hic-disorder/ds00559

Body dysmorphic disorder is a type of chronic mental illness in which you can't stop thinking about a flaw with your appearance — a flaw either that is minor or that you imagine. But to you, your appearance seems so shameful and distressing that you don't want to be seen by anyone. Body dysmorphic disorder has sometimes been called "imagined ugliness."

When you have body dysmorphic disorder, you intensely obsess over your appearance and body image, often for many hours a day. You may seek out numerous cosmetic procedures to try to "fix" your perceived flaws but never are satisfied. Body dysmorphic disorder is also known as dysmorphophobia, or the fear of having a deformity.

If you  have an eating disorder, often there is also an excessive pre-occupation with how you look and you can have both BDD and an eating disorder.

This is also a very informative article about it:

http://en.wikipedia.org/wiki/Body_dysmorphic_ disorder

BDD is often a symptom of an eating disorder, not an eating disorder in itself. It is the distorted perception of self. Sometimes it focuses on a single specific area of the body rather than all of oneself though this is not always the case.

I know someone who has BDD but no problems with eating, and she has a constant belief that her arms are so huge, flabby and disgusting (at her size, a petite though healthy weighted young girl, this is really really not true) that I have not seen her ever wear a short sleeved top in the five years I have known her. Ever. Even on hot days. She would cry when she was younger if people tried to get her to take her jumpers or cardigans off because she didn't want people to see her arms.

You can develop a distorted perception of yourself if you don't fuel and feed yourself properly. A starved brain has a starved reaction.

Yeah, I agree with lalabanana. People with ED's are usually BDD but people with BDD aren't always ED.

Thats sounds exactly like me.  Though I have food issues too, I hate my arms i will never wear short sleeves out in public either, doesnt matter if its 90 degrees out i cant do it.  idk though theres other things i dont like too just my arms are the biggest thing.