Don and Holly,
Maybe you guys should leave it up to the gynecologists- who know doubt will
never consider diet or coeliac disease (sorry guys). Missing periods in the
situation quoted may well be due to weight loss alone.  Once the weight loss
stops then the periods will probably come back. Pregnancy must be excluded
:-). There is a reasonable possibility of polycystic ovarian syndrome PCOS
(given prior overweight), while an ultrasound is helpful, the clinical
picture is essential.
I think omega 3 enriched Paleo diets (Paleomega diet) will turn out to be a
good treatment fro PCOS, but it will be years before any trials are
published.
The incidence of 1/150 makes it coeliac significant because it is a life
long problem. CF incidence of 1/150 doesn't matter as much if it's a one
off.

Ben Balzer