There’s no question that your diet affects your hormone levels. And if you’re a woman, that means what you eat heavily impacts your menstrual cycle.
While some women report fewer PMS symptoms and an overall easier time with menstruation after starting keto, many also claim that keto sent their cycles out of whack for the first few months.
In this article, we’ll explore the menstrual cycle, what’s considered normal once you get into ketosis, and how to mitigate abnormal cycles and symptoms — all while staying in a fat-burning state.
Before we jump into how a keto diet can impact your hormones and menstruation, it’s important to understand how your period works.
Menstrual Cycle 101
Every menstrual cycle has two primary phases: the follicular phase and the luteal phase. Here’s a breakdown of each:
The follicular phase begins on the first day of your period and lasts until you ovulate. At the beginning of this phase, your estrogen and progesterone levels are low, which stimulates a hormone called follicular stimulating hormone (FSH) to mature the follicles in your ovaries (which contain your eggs).
Throughout this phase, estrogen rises, peaking at ovulation — when your egg is released from your ovaries. If you want to get pregnant, ovulation is go-time[*].
Ovulation is the turning point between the follicular phase and the luteal phase. This occurs about halfway through your cycle and is marked by high levels of both FSH and luteinizing hormone (LH). During this time, estrogen levels fall briefly.
Following ovulation, you promptly begin the luteal phase, which is marked by a decrease in both FSH and LH. During the luteal phase, progesterone begins to increase and estrogen picks up again, but then slowly drops off.
By the end of the luteal phase, both estrogen and progesterone are low — which stimulates the follicular phase…and the cycle continues[*].
Get to Know Your Menstrual Cycle
Everyone’s cycle is different, so understanding how your personal cycle works is the first step in taking control of your health and hormones. And that means tracking. If you don’t already have some way of tracking your cycle, many apps and programs exist. A few examples are:
- My Period Tracker
- Eve Tracker
- Period Diary
Some trackers allow you to include symptoms, which can be helpful if you want to see how your cycle affects you both physiologically and psychologically.
Once you have a good idea of what your length looks like, you can divide it up into two phases; the follicular phase and the luteal phase. Don’t be surprised if your period doesn’t actually come every 28 days — a normal cycle can be anywhere from 21 to 35 days.
For instance, if your period comes every 30 days, your cycle will look like this:
- Day 1-15 follicular phase
- Day 15 Ovulation
- Day 16-30 Luteal phase
A tracker app will help you more accurately plan when your period is going to start, and when you can expect to start feeling symptoms of PMS.
Can a Keto Diet Affect Your Period?
The keto diet will affect everyone differently, depending on your current health status and other lifestyle factors, like exercise.
However, it’s normal for changes in nutrition and weight to affect your menstrual cycle.
Although weight loss and dietary changes can cause alterations in your cycle, the keto diet might also help with painful PMS symptoms.
Can the Keto Diet Help With PMS?
PMS, or premenstrual syndrome, brings up a different picture for almost everyone. For some, it’s a time when women just get a little moody or “spicey.”
For others, PMS results in debilitating symptoms that require days in bed, making them miss work or time with loved ones.
In reality, PMS is an epidemic issue in the United States.
Premenstrual syndrome is a catch-all term used for a wide range of symptoms that many women experience about a week to two weeks before their period starts.
It affects millions of women in the U.S. and is a combination of both physical symptoms, like headache and breast tenderness, and emotional symptoms, like anxiety, depression, and irritability.
The amount of discomfort you feel from PMS symptoms can vary greatly, depending on the status of your health and hormones. Some women can go for a walk to de-stress and find their balance, while others feel like they’ve been hit by an 18-wheeler.
- Breast tenderness
- Constipation or diarrhea
- Bloating and gas
- Sleep issues
- Food cravings
- Trouble with concentration
- Poor memory
- Mood swings
- Low libido
5 Ways The Keto Diet May Help PMS Symptoms
Many women struggling with hormone imbalances find it difficult to either fall asleep or stay asleep. If you’ve ever struggled with sleep issues, you know that a bad night’s sleep can ruin the entire next day.
Some people experience sleep disturbances during the first couple of weeks of a keto diet. That’s due to your body’s transition from a glucose-burning state to a fat-burning, ketone-producing state.
And it’s totally temporary.
In fact, most people report much better sleep quality once they’re officially in ketosis. And that may be due to a compound called adenosine.
Adenosine is known as a neuromodulator and plays a number of important roles in the function of your central nervous system. Well understood as an anticonvulsant for people with epilepsy, adenosine is also an essential chemical for moderating sleep behavior[*].
2. Balancing Insulin Levels
Keeping your insulin in check is crucial for the balance of your sex hormones. Your hormonal system is like a Jenga tower — when one piece falls out of place, the whole thing can collapse.
Okay, that was a bit dramatic, but the point is that nothing happens in your hormonal system in isolation.
Being in ketosis means that you’re limiting the amount of glucose in your blood. When glucose is low, insulin follows and will also stay low. The absence of excess insulin gives your sex hormones a chance to find their natural balance[*].
In addition, it may help to prevent insulin resistance and type 2 diabetes by increasing insulin sensitivity, which will further support your hormone balance[*].
One of the most common PMS symptoms is cravings. Whether it’s for sweets, salt, fat, or all of the above, something about getting your period makes many women feel out of control with food.
Ketosis can help with cravings in a couple of different ways. First, by lowering your carb intake, you’ll automatically control your blood sugar, a common sweets cravings culprit.
And second, being in a state of ketosis may help lower your “hunger hormone,” ghrelin[*].
You produce ghrelin in your stomach and that’s what stimulates your appetite. Its job is to signal you to increase your food intake and fat storage, resulting in weight gain.
By managing these two hormones, insulin and ghrelin, you’ll have a leg up on those pesky cravings that pop up once a month. Without those cravings whispering in your ear, you’re much more likely to make positive food choices and reap the benefits of avoiding the greasy, sugary meals that only offer temporary relief.
The ketogenic diet is highly anti-inflammatory. As you learned above, inflammation can wreak havoc on your hormonal system and cause fluctuations in your hormones that could lead to massive PMS symptoms.
When you’re in a state of ketosis your blood is flooded with ketones. And ketones are not only a fantastic alternative energy source to glucose, but they’re also anti-inflammatory.
Since many of the symptoms associated with PMS are also associated with inflammation, high levels of BHB may help to mediate some of the discomfort that comes with your menstrual cycle[*].
5. Trouble With Concentration And Memory
There’s nothing more frustrating than sitting down to do some work when your brain is clouded and foggy. Hormone imbalance, especially estrogen dominance, can result in brain fog and poor memory.
Ketones are like little superheroes for your brain. They’re anti-inflammatory, and your brain can use them even more efficiently than it does glucose.
In fact, during brain injury, the uptake of ketones by the brain increases significantly[*].
Many people report better memory, concentration, and learning when following a ketogenic diet. This is most likely due to an increase in the protein brain-derived neurotrophic factor (BDNF) as well as the enhanced bioavailability of ketones to the brain[*][*].
Can The Keto Diet Disrupt Your Menstrual Cycle?
For women that are still menstruating, there are a few things to look out for when beginning the keto diet.
Some women report that after beginning the keto diet, they notice disruptions in their menstrual cycle. Common complaints include irregular periods, heavier bleeding, periods cramps, and amenorrhea (loss of menstruation).
While there isn’t much research to support that ketosis itself can disrupt the menstrual cycle, some correlating factors come along with keto that may play a part. As your body shifts from glucose-burning to fat-burning, shifts in your metabolism, weight, and hormones may signal that it’s not time to focus on reproduction.
Rapid Weight Loss
Many women experience rapid fat loss when they begin the keto diet. As your body starts to burn fat for fuel, one often welcome side effect is weight loss.
Weight loss itself can be a great thing for balancing your hormones as it fights obesity and keeps your body operating efficiently (when you have weight to lose). When it happens too fast, however, it can send off alarm signals to your body.
Furthermore, estrogen is stored and produced by fat cells, which means that as you rapidly burn off your fat stores, it can cause an imbalance in your estrogen and progesterone levels. This is why many women that experience rapid fat loss (either on keto or any other weight loss plan) also tend to experience amenorrhea[*].
One of the benefits of the keto diet is a sharp reduction in food cravings. In addition, since you are no longer operating at the whims of insulin, you may also find that you feel satisfied longer and aren’t getting that “hangry” hit mid-afternoon.
As a result, most people following a keto diet find that they naturally end up eating fewer calories each day. While this can be a great thing for fat loss, when calories are reduced significantly, it can impact the hormone leptin.
Leptin is responsible for signaling to your brain that you have enough energy coming in from food. When leptin is in range, it tells your body that it’s safe to reproduce. However, when energy intake is low, leptin signaling dials down, and as a result, your brain gets the message that it’s not a safe time for reproduction. The result is something called hypothalamic amenorrhea.
Hypothalamic amenorrhea is your brain’s way of preserving energy for your body but shutting down your menstrual cycle. This is another reason why rapid weight loss (along with calorie restriction) can result in menstrual abnormalities[*].
Although the outcomes of a keto diet can be very beneficial, many people find the transition into keto to be stressful. Physically, your body is literally shifting its metabolic functions and sourcing fuel in a new way, which takes a lot of energy. Psychologically, following a diet that has strict guidelines can take a while to get used to, and for some people, it may significantly impact their family and social life.
One way that women’s bodies respond to stress is by slowing down the reproductive system. Again, if you’re not in the right condition for reproduction, this system will take a back-burner to allow for more vital functions to be carried out. As a result, many women experience menstrual symptoms associated with stress like painful periods, irregular bleeding (heavy or light), or missed periods[*].
Although you may experience some menstrual irregularity at the beginning stages of the keto diet, most women find that their cycles return to normal within a few months. Once your body gets used to its new way of operating, your system will settle into its new flow, and your cycle will likely return to normal.
Troubleshooting: 5 Tips For Keto and Hormone Balance
Don’t give up if you don’t see results right away. Your hormonal issues didn’t manifest overnight, and unfortunately, you won’t cure them overnight either. It may take a few cycles to get back into balance, so before you throw in the towel, try these tips that may help you stay the course:
1. Keep A Hormone Journal
You’re going to want to track your progress as you go. It can be very easy to forget how bad your cramps were a couple of months ago when you’re not feeling them anymore.
Or to completely forget how you once woke up in a sea of sweat when you’re now sleeping through the night.
Track any symptoms you’re currently feeling, old and new, through the month and pay attention to where you are in your cycle. This way, you’ll be able to identify the subtle changes that are happening in your body.
2. Test Your Thyroid
As mentioned earlier, none of your hormones work in a vacuum. When one is off, the others are most likely off as well.
One of the common hormones that can fall out of balance is your thyroid hormone. Low levels of thyroid hormone can reduce sex hormone-binding globulin (SHBG), which is responsible for binding to estrogen and testosterone. When SHBG is low, estrogen dominance can occur due to a decrease in binding[*][*].
Studies have shown that eating a super low-carb diet may cause an even more dramatic imbalance in your thyroid hormone. The thyroid needs a certain amount of carbohydrates to function optimally.
This may sound counter-intuitive since you’ve just learned about all the ways that low-carb can support hormone health, but even just 50 grams of carbs a day should be enough to keep your thyroid happy[*]. And that will definitely keep most people in a state of ketosis.
If you’re feeling very lethargic or know that you have a thyroid issue, try increasing your carbs slightly.
3. Move More
If you’re not moving your body in some way or another (walking, running, yoga, soccer, whatever floats your boat) every day then you’re missing out on an important aspect of hormone balancing.
Exercise can also help you balance your blood sugar. Female athletes following a ketogenic diet have higher levels of glucagon, a hormone involved in controlling blood sugar. As mentioned throughout this article, maintaining balanced blood sugar is a crucial cornerstone of hormone health[*].
4. Add Krill Oil
Krill oil has a whole host of health benefits due to its high omega-3 content. From heart health, to brain function, to hormone balance, if you aren’t taking krill oil already you may want to grab a bottle[*][*].
One study with 70 female participants found that supplementation with krill oil resulted in lower stress levels, enhanced mood, lowered irritability, and decreased use of pain medication[*].
Another chemical that can wreak havoc on your hormones is cortisol.
When you’re stressed out, cortisol increases a response known as the “fight or flight response.” This is an adaptation meant to protect us from over-thinking in situations where running or fighting are better than thinking and planning — like when a lion is chasing you.
Fortunately today we don’t encounter many lions in our day-to-day life, but our stress response hasn’t adapted to modern stressors like deadlines, traffic, and difficult bosses. So whether we like it or not, when we feel stressed our body wants to run from a lion.
The big issue with cortisol and hormone balance is that your sex hormones share the same precursor as cortisol — pregnenolone. When your stress is high, you use more pregnenolone to make cortisol, leaving little left for your sex hormones. This is often referred to as the “pregnenolone steal.”
Finding ways to deal with your stress so it doesn’t create the fight or flight response can be vital for balancing your hormones.
Foods and Supplements To Support a Healthy Cycle
Now that you know more about how keto can affect your menstrual cycle, here are some tips that can help you optimize your nutrition throughout the month.
During your follicular phase, your estrogen is on the rise. Most women have a love-hate relationship with estrogen — and for good reason. On the one hand, it’s crucial for your womanhood (it provides you with beautiful feminine curves) and helps keep your mood elevated through its relationship with endorphins like serotonin[*].
On the other hand, however, when it goes out of balance, it can wreak havoc on your entire hormonal system. Common symptoms like anxiety, depression, insomnia, water retention, brain fog, and more can develop when your estrogen levels remain elevated.
That’s why your follicular phase is a time to make sure you’re balancing your estrogen levels. Luckily, one of the most effective ways to manage estrogen is through food.
1. Focus On Cruciferous Vegetables
Cruciferous vegetables contain compounds that research shows can induce the detoxification pathways that remove excess estrogen from your body. Studies even indicate that cruciferous vegetables may be protective against hormone-dependent cancers like breast cancer in women[*][*][*].
Some cruciferous vegetables to increase during your follicular phase include; cabbage, broccoli, brussels sprouts, bok choy, cauliflower, collards, and kale.
2. Increase Fiber
Luckily, many cruciferous vegetables are also high in fiber — two birds, one stone if you will.
While the exact mechanism for fiber’s estrogen lowering effects haven’t been nailed down, it’s believed that changes in absorption and gut microbiome may be responsible[*]
Along with cruciferous vegetables, some other high fiber foods include; berries, chia seeds, avocados, nuts, and seeds.
Another way to combat high estrogen levels is to fight fire with fire. Consuming phytoestrogens (compounds from plants that have a similar chemical structure to estrogen) can influence estrogen metabolism in your body.
Due to their chemical structure, phytoestrogens can dock on estrogen receptors in your body, which results in altered estrogen metabolism. These compounds not only enhance the metabolism and excretion of estrogen, but they can shift the metabolism to less biologically active versions as well.
While different types of phytoestrogens exist, research shows that lignans found in flax seeds are more effective at neutralizing estrogen than the isoflavones found in soy[*].
In addition to flax, you can find lignans in foods such as sesame seeds, kale, broccoli, cabbage, brussels sprouts, and strawberries[*].
4. Reduce Alcohol
While you don’t have to give up alcohol entirely, if you experience symptoms of high estrogen, it’s a good idea to cut down your alcohol intake. Anything you can do to support your liver and help it detox out excess estrogen is going to help with overall hormonal balance.
During ovulation, many women experience some symptoms that are associated with PMS like cravings, bloating, and breast tenderness[*][*]. On the other hand, some women don’t even notice they’re ovulating and float through this phase seamlessly.
If you fall into the category of people who experience a little pre-PMS during ovulation, there are a few steps you can take nutritionally to support yourself.
1. Manage Cravings
If you know that your cravings for sweet or salty foods increase during the day or so of ovulation, you can get ahead of a face full of cake by:
- Managing your blood sugar levels
- Having some healthy but delicious snacks on hand
To manage your blood sugar, make sure that you start the day with a robust, protein-rich meal with plenty of healthy fats[*]. This could look like a protein shake or an omelet. In addition, make sure to eat regularly throughout the day. This likely isn’t the day to try a new intermittent fasting routine.
To combat your sweet tooth, prepare some satisfying fat bombs or other blood-sugar-friendly treats like keto cookies or keto brownies. If you fall into the “salty food” craving camp, make yourself some keto crackers or buy some beef jerky.
While several factors can influence your cravings, if you experience bloating around ovulation, you can be pretty sure that it’s hormonal. You can think of this as a little foreshadowing of your period[*].
To fight bloat during ovulation, eat foods that are high in vitamin B6. Some examples include; pork, turkey, eggs, salmon, tuna, chicken liver, and spinach[*].
Low potassium levels are also associated with bloating, so in addition to keeping your electrolytes up, you can try adding in potassium-rich foods. Some examples include; broccoli, spinach, mushrooms, cucumbers, zucchini, eggplant, and pumpkin[*].
3. Breast Tenderness
Vitamin b6 has also been shown to reduce breast pain that’s associated with your cycle. If you experience both bloating and breast pain around ovulation, it’s time to double down on those b6 rich foods[*][*].
During your luteal phase, you may start to experience symptoms of PMS. This is a time to get ahead of any menstrual discomfort but focusing on anti-inflammatory foods and nutrients that can ease symptoms of PMS like cramps, cravings, bloating, breast tenderness, mood swings, and more.
1. Anti-Inflammatory Foods
There are several things you can do nutritionally to keep inflammation at bay, but some of the most effective approaches are:
Eat More Omega-3 Fatty Acids
Some examples of high omega-3 fatty fish include; salmon, mackerel, herring, and sardines. If you’re not a big fish eater, you can also opt to take fish oil supplements, omega-3 algae supplements, or increase your intake of grass-fed beef — which is also high in omega-3 fats[*].
Sugar is one of the most inflammatory foods out there. If you suffer from PMS symptoms, avoiding sugar during this time of the month can make a big difference. In fact, research shows that the consumption of sugar-laden beverages is strongly tied to symptoms of PMS[*].
2. Fight Cravings with Fiber and Protein
Research shows that as estrogen increases, so does the hormone leptin — and vice versa. Leptin is a hormone that is released from your fat cells to let your brain know that you have enough fuel so you can stop eating[*].
When leptin is low, however, your brain doesn’t get the message that you’re satisfied, so you continue to crave food even when you’re physiologically satisfied.
During your cycle, your estrogen is at its lowest (and therefore so is leptin) at the end of the luteal phase (right before menstruation) and at the beginning of your period. It also takes a dip around ovulation. This explains why so many women experience intense cravings and urges to eat during these times in their cycle[*].
To combat these cravings during the luteal phase, make sure to keep your blood sugar steady. That means even if you’re following a keto diet, you should take care to eat regularly. If cravings aren’t an issue for you, then no worries — carry on as usual.
If cravings are an issue, however, take these steps to avoid a slip-up.
- Eat plenty of protein with each meal[*].
- Take extra care to keep carbs low.
- Have satisfying foods on hand like fat bombs, jerky, or whatever other low-carb treats put a smile on your face.
- Stay hydrated; many people often confuse hunger with thirst.
- Consume magnesium-rich foods (see the next section).
3. Increase Magnesium-Rich Food Consumption
But that chocolate is doing more than just satisfying your sweet tooth. When it comes to mood swings around your period, enhancing your magnesium intake may be the answer.
Research shows that women who take magnesium supplements experience a reduction in premenstrual depression and anxiety. In addition, they also experience a decrease in cravings[*].
Foods high in magnesium include; chocolate (go for sugar-free dark chocolate), brazil nuts, avocado, pumpkin seeds, leafy greens, and almonds [*].
4. Get More Vitamin B6
In addition to magnesium, vitamin B6 is an all-star when it comes to combating symptoms of PMS[*].
In addition, B6 may also help to treat PMS-related depression[*].
Foods high in vitamin B6 include; pork, turkey, eggs, salmon, tuna, chicken liver, and spinach
Menstruation marks the beginning of the follicular phase. While the recommendations listed above for the follicular phase apply during menstruation, there are some additional needs to be aware of while you bleed as well.
1. Red Meat
If you experience heavy bleeding, then it’s crucial to make sure you’re getting enough iron-rich foods in your diet. While research shows that taking iron supplements throughout the month is the best way to ward off anemia, during your period, it doesn’t hurt to make sure you’re getting in an extra dose of iron with some red meat consumption[*].
2. Fatty Fish
Many women experience cramps both during PMS and at the beginning of their period. For this reason, it’s beneficial to increase omega-3 intake during menses as well. As mentioned above, research shows that fish oil works better than ibuprofen for period cramps due to omega-3s[*][*].
If you’re not a fish eater then try incorporating other omega-3 rich foods during this time like grass-fed beef, chia seeds, spirulina, hemp seeds, or flax seeds.
3. Consume Magnesium-Rich Foods
If you tend to feel low and experience cravings during your period, there’s no better nutrient to focus on than magnesium. Several studies have shown that magnesium can reduce symptoms associated with menstruation — specifically food cravings and depression[*][*].
Foods high in magnesium include; chocolate (go for sugar-free dark chocolate), brazil nuts, avocado, pumpkin seeds, leafy greens, and almonds [*].
Due to the vast difference in sex hormones, women’s health and wellness look very different from that of men. This fact translates into all areas of health, and the impact of the keto diet is no different.
Many women report changes in their menstrual cycle during the first few months of keto. While a very low-carb diet may cause changes in menstruation, there are plenty of modifications you can make to your diet to ensure a healthy cycle.
A low-carb, high-fat diet supports hormone health and symptoms of PMS in a variety of ways including; blood sugar control, anti-inflammation, balancing cravings, helping with brain fog, and enhancing sleep quality.
The transition period known as keto-adaptation or “keto flu” may feel like you’re taking a step back, but if you stick with it, there are some fantastic benefits on the other side.