What is the definition of ed nos ? ..

of ENDOS ? ..
and is calorie restricting one ? ...

do you mean EDNOS?
if so it means, eating disorder none other specified, so yeah, calorie restriction is kind of, if its constantly on your mind, all you can think about.

ED NOS is eating disorder not otherwise specified
And no calorie restriction is not an eating disorder, it can however be a sign of an eating disorder, there are people simply on diets who restrict their calories...

DSM-I V Criteria:
The EDNOS category include disorders that do not meet the criteria for a specific eating disorder. Each one of the following disorders is an example:

For females, all of the criteria for anorexia nervosa are met except that the individual has regular menses.

All of the criteria for anorexia nervosa are met except that, despite substantial weight loss, the individual's current weight is in the normal range.

All of the criteria for bulimia nervosa are met except that binge eating and inappropriate compensatory mechanisms occur at a frequency of less than twice a week or for a duration of less than 3 months.

The regular use of inappropriate compensatory behavior by an individual of normal body weight after eating small amounts of food (eg; self-induced vomiting after the consumption of three cookies, or a five mile run for having two bowls of broth).

Repeatedly chewing and spitting out, but not swallowing, large amounts of food.

Binge eating disorder: recurrent episodes of binge eating in the absence of the regular use of inappropriate compensatory behaviors characteristic of bulimia nervosa.

http://en.wikipedia.org/wiki/Eating_disorder_not_otherwise_specified#DSM-IV_CRITERIA