Did you know that breakfast matters when it comes to your hormones and menstrual cycle?

The other day in class while studying the reproductive system, our slides reviewed the top natural therapeutics for menstrual pain and PMS. That list included increasing EFA intake (think flaxseed + walnuts) and decreasing animal fats the week before your period.

It also included eating mainly warming, cooked foods for those 7 days (which is what I’ve been saying for years!) and upping magnesium intake to 300-800mg/day. The last recommendation was “EAT BREAKFAST,” in reference to a 2003 study where skipping breakfast was associated with significantly higher scores of menstrual pain & discomfort among young women.

The study involved 439 Japanese women aged 18-20, whose breakfast habits were classified into three groups:

  • Group 1 has breakfast every morning;
  • Group 2 has breakfast 1-6 times per week;
  • and Group 3 has breakfast less than once a week.

The intensity of dysmenorrhea was then classified into three grades:

  1. Score 1, free of pain or slightly painful without the need for analgesic;
  2. Score 2, pain requiring analgesic; or
  3. Score 3, pain that cannot be not relieved by analgesic.

Their bowel habits were also classified into three groups (no more than once a week, 2-6 times a week, or every day).

Results showed that Groups 2 & 3 who skipped breakfast at LEAST once a week had significantly higher scores of dysmenorrhea compared to Group 1 who ate breakfast daily.

Women in Group 3 who skipped breakfast daily also showed a significant tendency towards constipation (Fujiwara, 2003).

A 2014 study in Egypt supported these findings with a group of 300 female students attending university. Their results showed a statistically significant increase in premenstrual abdominal pain, irregular menstruation and premenstrual cramping in participants who skipped breakfast vs. those who did not (Eittah, 2014).


This is my take on why skipping breakfast has this effect:

  1. Reason #1 – INFLAMMATION. If you skip breakfast, you’re obviously going to consume the bulk of your food intake later in the day. One study showed that for each 10% increase in the proportion of calories consumed after 5pm, there was a 3% increase in C-reactive Protein levels, which is a blood marker of inflammation used to predict the risk of cardiovascular events.
  2. Reason #2: INFLAMMATION… but this time due to elevated blood sugar levels. Again, skipping breakfast will lead you to consume your calories later in the day at lunch & dinner. In another study, when healthy adults ate 3 identical meals at breakfast, lunch, and dinner, their post-meal blood glucose increase was lowest after breakfast and highest after dinner! Even though the meals were exactly the same, their bodies were reacting & metabolizing in a completely different way depending on the time the food was consumed. Now these were just normal, balanced meals – no added treats or snacks. So imagine the difference between eating dessert in the morning vs. at 9pm when your body is most sensitive to sugar. I’m pretty sure none of us are ripping open a dark chocolate bar at 6AM, but I can bet we reach for a square or two in the evening. Especially the week before our period, and especially if we didn’t eat enough earlier in the day! Eating food late in the evening (particularly refined food or sugary treats) can raise your blood sugar levels too quickly. Then, as blood sugar spikes, omega-6 fatty acids are skewed towards a pro-inflammatory pathway, creating molecules called prostaglandins that turn ON inflammation. When pro-inflammatory prostaglandins are released into the bloodstream as the endometrial lining breaks down, the uterus goes into spasm, resulting in cramping & pain.
  3. Reason #3: CIRCADIAN RHYTHM. I’m sure you’ve heard that staring at the blue light of your phone late at night will throw off your internal clock aka your “circadian rhythm.” But did you know the timing of your food intake has an influence on your rhythm as well? Eating a hearty meal when you wake up in the morning supports your internal clock’s natural alignment with the environment’s photoperiod, whereas consuming a large meal at night can actually “reset” or throw off that clock. This results in misaligned metabolism, poor blood sugar control, and you guessed it – inflammation!

I always suggest that you eat *something* within 15-20 minutes of waking up, even if that’s just an apple or a sweet potato. It’s much better to go all out at breakfast than to work all day and splurge at dinner when you’re exhausted. 

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