When to stop fasting

I’m a mid 20sF who is worried about the menstrual irregularities that could be from fasting. I normally do omad or 20/4 but occasionally do 24-36 hr fasts as well. I haven’t had a period in 2-3 mo now. Last time this happened was in 2020 when I first got into fasting and went 7-8 mo without a period. I ended up with a ton of bleeding for months straight. Gynecologist said it wasn’t pcos from ultrasound and all. Birth control for a year fixed it but caused even more weight gain I’m trying to get rid of now. I’m Kind of worried about the potential cardiovascular/osteoporosis effects of amenorrhea I am overweight and I used to have regular cycles prior to the weight gain/starting fasting. I’m wondering if getting back to a normal weight would fix all these problems. My question is it better to continue fasting to get down to my GW and not worry about the periods or give up fasting and cico my way down? Recently came face to face with the weight and started fasting again in November. SW:217.2 CW:208.6 GW:170

Answer

You don’t have to do IF on the days around your period. If you have to stop fasting or go, say, 12:12 until you regain it is perfectly fine. You can focus on your diet in the mean time.

Being overweight can cause hormone imbalances, and that can explain a lot of what you’re going through.

So right now I’d focus on your diet (plus sleep and stress management) and see how that works on your hormones.

Answer

First, it was good you talked with your gynecologist.

Amerorhhea itself does not cause Cardiovascular/bone health problems. I think you are confusing it with increase in bone/cardiovascular risks in women who are post-menopause, which is a whole different thing, and a lot more than just not having a period!

After all, women routinely don’t menstruate for 9mo at a time during pregnancy, and after birth, often won’t menstruate for 6-12 MORE months if they are breastfeeding. Ultra-fit, heart-healthy female athletes who attain very low body fat often stop mentruating completely. A lot of healthy women have irregular periods. OTOH excess visceral fat CAN cause CVD, hormone weirdness, and other health problems.

If you’re still concerned, you could try cutting down to 18:6 for a couple weeks and see how your body reacts. It could be your body would be more comfortable with a less aggressive form of fasting. Find what works for you.