Menstrual Cycle Diet


If you’re anything like us then you probably were never taught much about how your menstrual cycle works during sex ed.


All you knew was that you have a period each month, it’s inconvenient and that it is your tool to get pregnant one day.


Maybe you’ve recently learned that there is so much to it, are excited to learn more but aren’t sure where to start.


If you’re nodding your head to any of that, I’m so glad you’re here. Today we’re going to take a deep dive into how the menstrual cycle works and how the very food you eat can support it.


Your  menstrual cycle begins at the onset of puberty, typically around age 12 – 16. At this time you have about one million eggs remaining that at some point can be fertilized for conception. However, just one of those one million eggs gets fertilized each month. Then, by the time you hit menopause, at around age 50 – 60, your egg count is close to zero. If you do the math, that equates to a loss of over 1,000 eggs per month during each period.


The menstrual cycle is complex but I am going to do my best to give you a brief snapshot into the most important things you must know about it. A regular period length is anywhere from 28 – 35 days. Anything shorter or longer can indicate hormonal imbalance. Each month you should ovulate at around day 14 of your cycle. This will depend on your cycle length and hormone levels. Keep in mind that not all periods are followed by ovulation. When ovulation doesn’t happen but a period does, we call this an anovulatory cycle. This is common in situations like hypothyroidism, PCOS, peri-menopause, or birth control use. Day 1 of your cycle is the first day of your period- this is called the follicular phase and lasts about two weeks until ovulation. During this time, the hormone estrogen is building up until ovulation. Ovulation can be detected by a change in basal body temperature and cervical mucus production. You can learn more about how to track your cycle here. You are most fertile in the four days leading up to ovulation. Once you ovulate, estrogen levels decline and the hormone progesterone takes over. Fertility chances abruptly decline to 0% a few days after ovulation occurs (see graph below).


When are women & men most fertile? - British Fertility Society | BFS

Source: British Fertility Society


Because progesterone levels rise during this time, so does your basal body temperature. That’s because progesterone is a very warm hormone. You may also notice that with your elevated body temperature that your resting heart rate increases and you become dehydrated quicker. Progesterone stays elevated for about two weeks until you start your period again. Once you start your next period, the menstrual cycle starts over.


When you can understand what changes are happening during your cycle you can begin to support your body’s needs. You work with it, rather than against it. You can then support or prevent pregnancy, depending on your goals.


There are technically four phases of the menstrual cycle: follicular, ovulatory, luteal and menstrual. However, I like to break the cycle into two parts: pre-ovulation and post-ovulation when we talk about lifestyle adjustments.


Pre-Ovulation: [The two weeks between starting your period and your fertile window]

During this time estrogen is at its peak. Because estrogen is the dominant hormone, you have better insulin sensitivity. Insulin is a hormone made by our pancreas that helps us utilize carbohydrates in our diet. You will want to ensure that each meal contains fiber-rich starches and vegetables as these will soon support your progesterone production in the coming weeks. You also may notice an increase in energy levels for workouts. Now is the time to push yourself more with heavier weights and intensities. If you are prone to ovulation breakouts, cramping or tender breasts, incorporate these items into your daily routine: cruciferous vegetables, spearmint or green tea, salmon and extra virgin olive oil.


Post-Ovulation: [The two weeks before starting your period and after your fertile window]

During this time, progesterone is the queen hormone. Progesterone increases our active thyroid hormone levels. Because of this we see an increase in metabolic rate. That hunger you experience right before your period? You’re not crazy, it’s a physiological response. Although carbohydrate tolerance may not be as supreme as the first half of your cycle, you do want to add in the equivalent to an extra snack per day. You will want to prioritize protein and hydration during this time. Your body is more prone to breaking down muscle and to dehydration. You may also get sick easier so it’s best to listen to your body, prioritize sleep and limit alcohol intake. Some women find that eating or supplementing with food-rich sources of zinc, vitamin C, elderberry and astragalus can also help. The late luteal phase is a perfect time to take a de-load week from workouts. This is where you scale back the intensity and volume of your workouts. If you experience PMS symptoms like severe cramping, headaches, breakouts and mood changes, check out my mini-course “Put and End to PMS.”


I teach you more about how to eat and exercise with your cycle in my monthly membership, Strength in Hormones. When you join you get access to a pre-recorded training on Eating Throughout the Cycle as well as my Cycle Syncing PDF resource. Plus you receive monthly hormone supportive recipes and workouts and so much more. Learn more and join at www.functionalfueling.com/sih.


I share more cycle and hormone balancing tips over on my Instagram @nutritionwithlo.


Written by: Lauren Papanos, MS, RD, CSSD

Comments +

Leave a Reply

our services

become a member

book a consult

advanced lab testing

functional medicine nutrition

herbal medicine

hormone smart exercise