If the week before your period is the week your fasting falls apart, you’ve found a pattern, not a flaw.
What’s happening in there?
After ovulation, progesterone rises and brings a set of changes with it. Measured day by day, body temperature goes up and stays up, resting heart rate runs higher, and mood sits a little lower.1
Appetite is the one you’ll feel most. The research consistently describes intake rising in this stretch, with cravings reported more often by women who get premenstrual symptoms.3
A study that followed women across several cycles with repeated blood draws found that lower progesterone in this phase went along with stronger cravings.2
The hunger has a cause, and the cause is not you.
Your body is also running slightly warmer, which costs a little more energy. Small, real, and enough to notice when you’re already hungry.5
What should you change?
- Shorten the window by an hour or two. As the plan for this week.
- Put more food in it. Under-eating in your luteal week is how this unravels.
- Protein and something warm earlier in the day. Does more for the evening than anything you do in the evening.
- Expect worse sleep. Plan a lighter week.
- Skip a day if you need it. This is exactly what rest days are for.
What if it’s more than hunger?
Premenstrual symptoms run on a wide scale. At the severe end, premenstrual dysphoric disorder affects a small minority of women, with pooled estimates landing at a few percent depending on how strictly it’s defined.4
If the days before your period reliably bring something that disrupts your life rather than just annoys you, that’s worth a conversation with a doctor. It’s treatable, and no amount of adjusting your eating window touches it.
And then?
The week after your period is usually the easiest fasting of the month. Nobody says this part.
If you had a hard luteal week, you haven’t lost anything. The next stretch tends to hand it straight back.