Help! Missed Period After Fasting!

by Mike S.

Hello:

If anyone who is experienced in this can help it would be greatly appreciated. We're kind of freaking out.

My girlfriend recently has decided to start fasting one day a week. She started this about 6 weeks ago, the last week of November or so (though she skipped Christmas Day.)

On fasting days she typically only drinks about 4 glasses of water with apple cider vinegar and honey, and several other glasses of water, very low calorie except for the honey--- maybe 200-300 calories a day.

In the last 5 weeks with the fasting she has lost about 10 pounds which is about 8% of her body weight. She is of athletic build.

Her BMI is now about 20. She says she has never lost this much weight this quickly. She eats a varied omnivore diet otherwise-- she's not a vegan, but doesn't drink milk.

Anyway, her period was due around December 31. She typically averages about a 30-33 day cycle, it varies, but is regular.

She has only ever missed one month in her life about 12 years ago when she was traveling, and it's never been longer than 33 days. Anyway, it is now day 37 with no period and we are concerned about two things: pregnancy and her health.

What we want to know is, is it possible that she has missed her period because of the fasting and rapid weight loss? We haven't tested for pregnancy yet. It seems unlikely that she is pregnant, though there is a non-zero possibility. Also, she is concerned that the fasting may have injured her in some way.

She hasn't done any long term fasts, just a one day fast four weeks in a row with weight loss of about 8% of her body weight.

Any advice would be appreciated!!!

Thanks!