Eating for your menstrual cycle: what to eat in each phase

The cycle is not just "your period": 4 phases, 4 needs

The menstrual cycle lasts an average of 28 days (21 to 35 is normal) and divides into four phases, each with a distinct hormonal profile: menstrual, follicular, ovulation and luteal. Those hormones do not only regulate fertility; they also influence how much energy you burn at rest, how hungry you are, how you handle carbohydrates and how much water you retain. That is why eating exactly the same for all 28 days ignores half the information your body is giving you.

What the science says: your metabolism changes across the month

It is not perception. Metabolic-chamber studies (the gold standard for measuring energy expenditure) show that basal metabolism rises in the second half of the cycle. Webb's classic work (Am J Clin Nutr, 1986) measured resting expenditure an average of 8-10% higher in the luteal phase than the follicular, and later reviews like Davidsen (Int J Obes, 2007) confirm that spontaneous energy intake also increases before the period. Translated: that "I am hungrier before my period" has a measurable hormonal basis, it is not weakness.

What to prioritise in each phase (summary)

Menstrual phase (days 1-5): replenish iron

With bleeding you lose iron, which is why women of childbearing age need more than men (about 18 mg/day vs 8 mg). Iron deficiency is one of the most common causes of fatigue in women. Energy is usually low these days, so it is not the time to cut calories: it is the time to eat wisely.

• Heme iron (absorbs better): lean red meat, turkey, mussels, sardines.
• Plant iron: lentils, chickpeas, tofu, spinach, quinoa — ALWAYS combine with vitamin C.
• Vitamin C to absorb iron: peppers, citrus, kiwi, strawberries, tomato.
• Magnesium for cramps and mood: dark chocolate, nuts, seeds, legumes.
• Avoid coffee or tea with iron-rich meals (they reduce its absorption).

Follicular phase (days 6-13): your best window

After your period oestrogen rises and, with it, your insulin sensitivity and your performance. It is the phase in which you tolerate carbohydrates best and usually have the most strength and energy to train. Make the most of it: prioritise protein to build and repair, and complex carbs to perform. If you train strength, this is the fortnight to go for your best numbers.

Ovulation (~day 14): hydrate and add colour

At ovulation oestrogen reaches its peak and body temperature rises by about 0.4 degrees, which slightly increases your water needs. Drink a little more and go for foods rich in antioxidants (berries, deeply coloured vegetables, green tea). It is a short phase but a good moment for fresh, light meals.

Luteal phase (days 15-28): manage the hunger, do not fight it

This is where most diets derail. Progesterone rises, basal metabolism increases 5-10% and appetite grows — all physiologically. If you try to eat the same as in the follicular phase, you will go hungry and end up bingeing. The winning strategy is to get ahead: more satiating meals with protein, fibre and complex carbs, which keep glucose stable and cut cravings before they appear.

Premenstrual cravings: why they happen and what to do

In the late luteal phase serotonin (the well-being neurotransmitter) and glucose tolerance drop, a combination that triggers the desire for sugar and chocolate. It is not a character flaw: it is brain chemistry. Fighting it with pure willpower almost never works. What does work is not arriving ravenous (regular, satiating meals), giving yourself a controlled treat instead of banning it, and covering magnesium, which the body seems to ask for specifically through the chocolate craving.

If you take hormonal contraceptives

Important: the pill, ring, patch or hormonal IUD provide synthetic hormones that flatten the natural fluctuations of the cycle. If you use one of these methods, the per-phase variations in hunger and metabolism practically disappear, so it makes no sense to "cycle" your eating. Eat for your goal steadily all month.

How to apply it without obsessing

You do not need four different diets or a complicated calendar. Keep three ideas: on your period mind your iron, in the follicular phase make the most of it to train and eat well, and in the luteal phase anticipate the hunger with satiating food instead of resisting. The rest is the usual — enough protein, real food and consistency. The difference is that you now stop blaming yourself for being hungrier some days: it is simply your body doing its job.