Intermittent fasting for women living with PCOS

Written by Aly Owen

Medically reviewed by Louise Bula, RD

Published on June 29, 2023 | Updated on June 18, 2024

According to the CDC, polycystic ovary syndrome (PCOS) affects up to 12% of women / people with ovaries in the US. If you’re one of those five million people, you’ve probably been on the hunt for ways to manage your symptoms. 

As an eating routine associated with weight loss,[1] reduced inflammation,[2] and improved insulin sensitivity,[3] intermittent fasting sounds like it could be a good fit. Plus, it’s also pretty versatile and easy to follow, so you won’t have to spend loads of time (or energy, money, etc.) prepping your pantry or bending over backward to accommodate routine changes. 

But is intermittent fasting for PCOS something people do? And if it is, is intermittent fasting good for PCOS, or are PCOS and intermittent fasting more of an “oil and water” situation? 

If you’re wondering whether fasting for PCOS is a potential recipe for success or disaster — and if so, for whom and in what conditions — you’re in the right place. 

One important note upfront, though: you should always get approval from your primary care provider before making any changes to your eating habits or lifestyle that could impact your health, especially if you have an existing health / medical condition like PCOS. 

(Psst! If you’ve been having a “What the heck is that?” moment ever since we mentioned “intermittent fasting,” you may want to skip to our guide on intermittent fasting for beginners before reading on!)

Is it okay to intermittent fast when you have PCOS? 

If you’re reading this article as a person living with PCOS, you probably already know all too well that women / people with PCOS can experience a range of reproductive, metabolic, and psychological symptoms,[4] including things like: 

• infertility 
• missed, irregular, or very light periods
• increased anxiety and depression
• weight gain
• excess body hair, including on the chest, stomach, and back 
• insulin resistance 

(If you suspect you have PCOS but aren’t sure, your doctor is the one who can give an official diagnosis.)

Let’s cut to the chase without more of a pathology lesson: intermittent fasting may help manage many of the above symptoms and lower the risk of experiencing them in the first place. 

For example, it may decrease certain hormones (like ones that cause excessive hair growth) [5] and increase certain protein-binding hormones (like ones that improve insulin sensitivity) in people living with PCOS. Likewise, for people in general, it may support safe, effective weight loss,[1] which can, in turn, support insulin regulation and better blood sugar metabolism.[3] There’s even a study that suggests time-restricted eating can improve menstruation, hormone levels, insulin resistance, and chronic inflammation.[6] 

So, is intermittent fasting the secret ingredient for cooking up your perfect PCOS management plan? 

Not necessarily.  

While there’s lots of promising data linking intermittent fasting to improving conditions associated with PCOS, more research is needed to answer “Is fasting good for PCOS?” more definitively. Specifically, we need to understand how different fasting approaches affect certain PCOS conditions and whether any improvements are associated with PCOS directly or changes to other health-related elements, like body weight. Likewise, intermittent fasting may exacerbate or influence disordered eating behaviors (which is why we don’t recommend it for anyone with a history of or currently diagnosed with disordered eating).[7] Plus, its ability to affect blood sugar levels can be dangerous for people with insulin-related conditions.

To boil that down to something simpler, for women / people living with PCOS, intermittent fasting should only be on the table after your healthcare provider has signed off on it, especially if you have blood-sugar-related conditions or broader concerns around fertility and getting pregnant. 

If you’ve gotten the all clear, but you’re not sure if intermittent fasting is “your thing” — or you want to learn more about intermittent fasting for women / people — you can take our Simple quiz. Through that, you can discover your options, get customized advice, and find answers to common fasting-related questions like “Is fasting good for you?” “Is intermittent fasting safe?” and “Does intermittent fasting slow metabolism?” Whether you’re a fasting newbie or a total pro, we’ve got your back (and your whole body, mind, and soul!) in finding what works best for you.

But wait, how do PCOS and intermittent fasting interact? 

Before we dig into how fasting and PCOS work in tandem, let’s take a look at how each one works individually. 

PCOS happens when the ovaries or adrenal glands of an assigned female at birth produce more androgens (a type of hormone) than normal during the reproductive years.[8] Everyone experiences PCOS differently, and it’s more common in people living with obesity [9] and people who have relatives with PCOS,[10] but broadly speaking, having PCOS can increase your chances of developing lifestyle-related conditions, including type 2 diabetes and heart disease.[11]  

While there’s no cure for PCOS, improving your eating habits and physical activity levels is recommended.[12] Your doctor may also prescribe certain medications to help alleviate some symptoms. Enter intermittent fasting. 

Intermittent fasting involves switching between periods of fasting and periods of eating on a regular schedule — in other words, taking a complete break from eating (and drinking anything with calories) for a defined period of time.

This break from calorie consumption works to trigger a fasted state, a natural body phase where you’re dipping into personal power reserves and using up fat instead of recently-digested sugar to keep your body going. 

When your body is in this fasted state, it can experience a whole bunch of health benefits if the process is managed carefully and intentionally, like reduced insulin resistance, more stable blood sugar levels, and lower systolic blood pressure. It can also promote better cardiovascular, brain, and metabolic health.[13,14,15] 

So basically, the process of intermittent fasting may unlock potential benefits that may help improve some PCOS symptoms and diminish related risk factors.

The keyword there is “may”: intermittent fasting may have certain effects, and these effects may benefit PCOS-related symptoms and risk factors. 

Unfortunately, combining intermittent fasting with PCOS isn’t the perfect blend for everyone because both fasting and PCOS affect bodies differently. Fasting can also throw a mean curveball for women / people who have PCOS and are taking medication to lower their blood sugar. That’s why working with a healthcare professional is super important if you’re planning on concocting a meal plan around these two ingredients.  

Common side effects of intermittent fasting with PCOS 

If you’ve ever had to snag emergency sanitary products from friends, you’ve probably realized that bodies can experience the same phenomenon at the same time very differently and to very different degrees. 

The same is true if you mix PCOS and fasting. There’s no guarantee that your beautiful, unique self will have the same experience or reap the same benefits as your friend, colleague, or neighbor. There’s also no way to tell how many (if any) side effects you experience along the way and how fleeting or persistent they may be. 

How do you know if something is “normal bad” or “be concerned bad”? Our bottom line when it comes to side effects is that your health isn’t worth a gamble. You know your body better than anyone: while some standard intermittent fasting side effects are pretty common for a week or two as your body adjusts, if something doesn’t feel right, don’t hesitate to reach out to your healthcare provider. 

There are a few potential side effects that women / people with PCOS may be particularly susceptible to or challenged by, so pay particularly close attention to the following: 

• Hypoglycemia or hypoglycemia. Fasting causes fluctuations in blood sugar levels, and people living with PCOS, especially those with type 2 diabetes or who are taking blood-sugar-lowering medications, are especially sensitive to these fluctuations since they often have inherently higher levels of insulin and blood glucose. Situations in which blood sugar levels drop too low (hypoglycemia) or spike too high (hyperglycemia) can be dangerous and even life-threatening — another reason you should get medical approval before intermittent fasting! 
• Changes to menstrual cycles. Even though intermittent fasting may improve hormonal regulation in people with PCOS [5], these changes to your hormone balance may, in turn, affect your cycle, particularly if you already experience irregular or disordered periods. If you notice any changes, check in with your doctor.  
• Increased cortisol production. Some studies suggest women / people with PCOS may already be prone to higher levels of cortisol (a hormone that, in high concentrations, can lead to high blood pressure and high blood sugar).[16] Take on changes to your eating routine — which can bring on stress, another major contributor to increased cortisol production [17] — and you’ve got yourself a surplus of this hormone. You never want your eating routine to be something that’s causing additional stress / anxiety, so if that’s the case, talk to your healthcare provider — they can really help you. 
• Disordered eating. Although intermittent fasting is a pretty loose and flexible eating routine that can be adapted to your needs, preferences, budget, goals, and lifestyle, it still involves sticking to a schedule for at least part of every week. Since people with PCOS are often already advised to reduce their carbohydrate intake (in order to manage insulin and blood sugar levels),[18] layering more food-related “rules” can add unnecessary stress. Food and calories are never inherently good or bad — some choices are just more health-promoting and nutrient-dense than others — so you want to keep an eye on yourself rather than obsess over your plate. If you’re preoccupied with your food routine or find that it’s making you anxious in any way, it’s time to reconvene with your healthcare professional. 

5 tips on how to intermittent fast with PCOS 

So, you’ve double-checked with your doctor that fasting could be a good fit for managing your PCOS symptoms.

Now what?

Here are our top tips for giving yourself the best chance at making intermittent fasting + PCOS = a happy, healthy you while avoiding pesky intermittent fasting mistakes. 

1. Start small. Safe, effective intermittent fasting that leads to long-lasting results is always a gradual process, so there’s no need to approach it with the pressure of a Chopped episode. We recommend starting with a time-restricted eating schedule that extends the natural fast you undergo while sleeping. “More” also isn’t “better” when it comes to fasting — longer fasts (i.e., those beyond 18 hours) introduce more risks.
2. Eat early. The best eating routine is one you can stick to without creating additional hurdles for yourself. Some people may find it easier to manage blood sugar levels if they have breakfast to kick off their day, so if that’s the case for you (or you just can’t live without that latte and granola combo to get you out of bed!) have a slightly earlier dinner and break your fast in the morning. You can also always take our Simple quiz to see which schedule(s) might be the perfect match for your needs, preferences, and lifestyle.
3. Build a PCOS-friendly meal plan for your eating windows. What you eat plays a big role in treating PCOS symptoms,[19] and just because you’re eating less or for less time doesn’t mean your body needs less nutrition. We’ll look at how to build a PCOS intermittent fasting plan in the next section, but for now, think health-promoting, nutrient-dense foods (e.g., whole grains like oats and quinoa, lean proteins such as fish, eggs, and tofu, healthy fats like avocado, plus fruits and vegetables) that keep your blood sugar stable for longer.  
4. Drink lots of fluids. Our body thrives on water — it’s made of a lot of it, after all! — so staying hydrated is incredibly important for any fast. Keep topping up that water bottle, though coffee and tea (without any cream or sugar) and one or two cans of diet soda are okay, too.
5. Cut yourself some slack. Your body is part of what makes you “you.” Even if it feels like you’re in a constant battle with it, you’re both working toward the same goal of keeping you in fighting shape. Respecting your limits and practicing self-compassion over self-judgment will support all parts of you working in harmony. Having regular “how’s this feeling” check-ins can also help keep you on track with your goals and needs while ensuring you spot any potential problems or safety issues early.  

Dieting and fasting safely with PCOS 

We’ve already covered some potential benefits and some potential side effects that can happen if you try intermittent fasting with PCOS.  

But when it comes to managing PCOS symptoms like insulin resistance, glucose intolerance, and weight gain along the way, how do you do so safely?

Like any good recipe, the key lies in both the quality of the ingredients and how you put them all together. In the previous section, we outlined our tips for the latter, so what about those “ingredients”? 

In this case, those “ingredients” are the fuel you give your body. 

Or, in other words, food and drink. 

Alongside lifestyle factors like psychological well-being, sleep quality, and physical activity levels, your diet is a big influence on your experience with PCOS, especially when it comes to insulin resistance.[20] Creating a safe, effective fasting approach that may ease your symptoms means filling your eating windows with vibrant, nutritious foods that will delight both your tastebuds and your body. 

We’ve put together more general guides on what to eat during intermittent fasting and what you can drink while fasting. However, when it comes to fasting with PCOS, here’s how to power up your pantry. 

How to build a PCOS diet safely 

Whether you’re adapting your PCOS eating routine approach to help with a specific symptom or health goal or to support better overall health and well-being, certain munchies pack a more powerful punch in terms of nutrition. 

Broadly speaking, we recommend not overdoing it on the carbohydrates for people with PCOS. That means eating less than 150 grams daily (or around 10 servings).[19] Not all carbs are created equal, though, so focusing on fiber-filled, low-glycemic-index whole grains, fruits, and leafy vegetables over things like white rice, starchy vegetables, and sugary drinks will help maintain steady blood sugar and keep you fuller for longer. Plant-based proteins (like beans, lentils, and seeds) and lean animal proteins (like turkey and chicken) also help with that. You likewise want to include healthy fats (like olive oil, nuts, and salmon) and limit ultra-processed things (like anything fried or steeped in extra sugar and preservatives).

That said, we know it can be tough to argue that a salad will satiate a pizza craving — no matter how many croutons or how much cheese you sprinkle on top — so creating a safe, sustainable, and satisfying eating routine also means allowing a little wiggle room. We’ve seen what all work and no play did to Jack in The Shining, so before you start reaching for the hangry axe of doom, make sure you’re not weighing yourself down with too many restrictions.

Ultimately, enjoying what you eat is important — even babies will tell you (or show you by spitting it back at you) that force-feeding food you don’t like just isn’t going to work long term. Stock up on the health-promoting foods that you actually enjoy to keep that motivation going and your soul happy. 

When should you consult a doctor or a dietitian?  

We believe you should always work with your doctor / registered dietitian when you’re planning a meal plan to support your PCOS or making any changes to your habits that could affect your health. It’s their literal job to figure out what’s best for you and your unique body, and no matter how advanced AI gets, these (human) care providers will always be able to give you more accurate and personalized advice than Google. 

If they’ve already approved the plan, but you’re experiencing persistent / severe side effects, new symptoms like abdominal pain or fainting, or spotting / irregularities with your period, it’s time to break the fast and reconvene with the professionals. 

Even if something just feels off, but you can’t quite figure out what or how, keep an eye on it — that little gnat of weirdness at the edge of your awareness may be the first sign of a reason to change your approach. 

While results from fasting can take time to notice, you should also always check in with your healthcare team if you find yourself several weeks deep in the “intermittent fasting not working” dumps. They’re there to help support you and help you troubleshoot, especially through difficult and frustrating times. 

Written by Aly Owen

Medically reviewed by Louise Bula, RD

Published on | Updated on June 18, 2024