Bulimia. Although it's forced vomiting not voluntary.
Not usually. However, like humans, they could suffer an eating disorder such as pica. Pica is when you eat things that are not food.
Not in and of itself, but not wanting to eat can often be a sign of an eating disorder or a much more serious health problem.
Yes. That is a sign of the dangerous (and potentially fatal) eating disorder known as bulimia.
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.
Not eating / starvation is usually a sign of the eating disorder known as anorexia.
People who don't eat / starve themselves often suffer from a disorder known as Anorexia.
If you eat a disco ball you probably have an eating disorder known as "PICA." It is an eating disordered diagnosed when a person eat nonfood items.
Anorexia
It is said that eating grass is good for a dog because it helps his digestive system, but my dog always vomits shortly after eating it, so I'm not sure.
It is known as 'B.E.D', or 'Binge Eating Disorder' (also called Compulsive Overeating). It is an official eating disorder listed in the DSM-IV.
Why do that? It's nobody's business about your eating disorder. Just tell them, "Je ne veux pas," "I don't want it."
Anorexia nervosa I think.