Is a Low Carb Diet Good for PCOS?

Dr. Jolene BrightenPublished: Last Reviewed: PCOS Leave a Comment

If you’ve been following me (and if you are new, welcome), you know I embrace a root-cause approach to women’s wellness versus a band aid that may help short-term but doesn’t go deep enough to make a long-term difference. 

So when I get so many questions about low carb diets and PCOS, I know it’s time to address it, especially when it’s estimated that PCOS affects up to fifteen percent of women globally. Low carb diets like keto keep gaining popularity, but are they actually good for women to follow long-term?

In this article, I’ll share why low carb could help short-term, but also why it’s not a cure-all for all women. I’ll also share some tips on PCOS management and resources to help you learn more.

What is PCOS?

Polycystic ovary syndrome (PCOS) is a hormonal disorder linked to insulin resistance and inflammation. Insulin is the hormone that regulates your blood sugar, so insulin resistance means your cells are resistant to the insulin’s signals. As a result, your blood sugar stays higher than it should. 

Up to 70 percent of women with PCOS have insulin resistance, regardless of weight status. As a result, there’s a close tie between women with PCOS and an increased risk of metabolic syndrome

Women with PCOS have higher than average testosterone, which throws off overall hormone balance. As a result, hormone-related symptoms like acne, facial hair, mood swings, or heavy periods are all part of the picture. Insulin resistance also plays a role in producing even more testosterone, creating a vicious cycle.

Every woman with PCOS may present differently, but symptoms can also include issues with fertility, irregular or missing periods, hair thinning, depression, headaches, and weight gain.

Since inflammation and insulin resistance have close ties to what we eat, many women turn to diet for symptom management.

Is Keto Good for PCOS?

Since the keto diet is so popular right now, whether it’s good for PCOS comes up a lot. The ketogenic (keto) diet is known as a very low carb diet. Carb intake is restricted to less than fifty grams a day while dietary fat increases to put the body into a state of ketosis. Ketosis is a physiological response where the body uses fat for energy instead of carbs.

When carbs aren’t limited, they are the primary fuel for the cells in your body. After eating carbs, they are broken down into sugar (glucose). Your cells can then use glucose for immediate energy or store excess in the liver, muscles, or as fat. 

Since insulin resistance drives PCOS exacerbation, low carb diets are often touted as the answer. Some may argue that keto or low carb diets are good for women with PCOS because they address the root cause of insulin resistance. 

But a thoughtful question is: is going low carb really the ultimate solution?  Are some women just forsaken to a lifetime of carbohydrate restriction?  Do some women have to always choose: carbs or health? Which do I want more?  What if there was more to the story than that and the approach to managing PCOS wasn’t so reductionist?

Well, it turns out, women with PCOS aren’t necessarily carb resistant, and not all carbs need to be vilified. There are even certain types of carbohydrates that are important for hormone balance. While lowering overall carb intake from refined sources like pastries, white bread or juice can benefit most women, very low carb diets like keto may not be necessary to see results.

Low carb and keto can work for some women, but they aren’t a cure-all. And they certainly are not a long-term solution for true health. But I understand sometimes we need to see the needle shift and in certain circumstances it might be a helpful step towards your goals to try low carb. Here are some of the pros and cons to consider:

Are There Benefits of a Low Carb Diet for PCOS?

Generally, low carb diets can help support your blood sugar by reducing, or in the case of the keto diet, removing most carbohydrates. Without carbohydrates, you won’t see the quick spikes seen with high carb intake, especially simple carbs like sweets or white flours. Less carb intake also means insulin production drops, helping to lower the inflammatory burden in the body. 

As a result, low carb diets have improved blood dysregulation in research. For example, a four-month low-calorie keto diet intervention for women with type 2 diabetes improved blood sugar, both fasting and A1c (a marker of long-term blood sugar levels) and led to more weight loss than following a typical low-calorie diet.

Low carb diets could also help with weight loss due to fat-burning efficiency and influence on hunger hormones. Since the body switches to ketones for energy, it can help women with difficulty losing weight shift into a metabolic state that promotes fat burning. However, research suggests that when it comes to long-term weight loss, there isn’t a difference between low carb diets and other types of diets. What matters more is following a pattern of eating that is sustainable for your lifestyle.”

A recent systematic review of twenty dietary interventions for women with PCOS found that a low-carb diet significantly improved fertility outcomes and hormone balance. While this is good news, all but one of the studies was six months or shorter, so it’s hard to say whether women could (or should!) stick to the dietary interventions long term. 

A very small pilot study on women with PCOS also found that a ketogenic diet with fewer than 20 grams of carbs a day resulted in positive changes in body weight, hormones, and fasting insulin. However, it’s interesting to note that of the eleven women who started, only 5 completed the study. It’s possible that the diet was just too much for some of the participants, although the authors didn’t share this. 

A similar small study on women with PCOS found that following a ketogenic diet improved insulin resistance, blood lipids, hormones and helped with weight loss. The study also included herbal supplements to support side effects. Once again, the study was only three months, so more research on long-term benefits is needed, especially for women with PCOS.

What are the Cons of a Low Carb Diet?

I want to point out that low carb and keto can mean very different things. While keto severely restricts carbs, a low carb diet doesn’t have to be as extreme. For women with PCOS cutting some carbs can be very helpful. It’s just that it could be a problem when the restriction goes too far.

The central question is whether you need to restrict carbs that much or can women with PCOS see similar results without removing nearly all carbs? In my experience, the answer is yes. Further, following a very low carb diet may not be healthy for many women long-term, and here’s why.

Carbohydrates and Stress Hormones

Women are more prone to the adverse effects of stress. Low carb diets, especially keto, put the body in a state of stress. For some women who follow keto, the significant reduction in carbs leads to a big calorie deficit which may sound good for weight loss, but it can be terrible for your hormones. 

Dropping calories too low can stress the adrenal and reproductive system in a way that shifts the body into protective mode. Our hormones are so sensitive to stressors of any kind—external or internal—so one of the first things to go if the body doesn’t feel safe is our periods. The last thing you want to add to a condition characterized by hormone imbalances is to fuel the fire by further stressing your body.

Plus, what I’ve seen in practice with so many women is that restriction almost always leads to extremes in the other direction. Some people find it easy to follow keto, but many eventually feel deprived. Once you stop the keto diet, carb cravings can come back with a vengeance, not a great thing for anyone, especially women with PCOS.

Do women with PCOS need to be mindful of the types of carbs they eat and how they pair those carbs with other foods? Yes. But vilifying carbs as a whole doesn’t work for all women, especially since women with PCOS are also more likely to suffer from eating disorders. Putting a woman on a highly restrictive diet who is already prone to disordered eating patterns probably isn’t such a good idea.  

Low Carb and Thyroid

Keto could also negatively impact your thyroid. While more research is needed, some studies indicate that a keto diet could induce hypothyroid in some cases. You need glucose to produce thyroid hormone, so cut back too far on carbs, and you could be adding a sluggish thyroid to your PCOS picture, definitely not what you need.

Low Carb and Gut Health

Keto diets also can come with a handful of not-so-pleasant side effects like constipation, bad breath, and what has been coined “keto flu.”  Keto flu feels like the real flu with body aches, fatigue, nausea, and headaches and happens as the body adapts to ketosis. While it should pass after the body adjusts, some notice they still don’t feel well after several weeks. 

Traditional keto also removes some of the very nutrients needed for healthy hormone balance from fruits and veggies. Appropriate amounts of glucose are critical for hormones, and fiber (a carbohydrate) keeps our gut bacteria healthy and happy. Several studies have pointed out the potential negative impact very low carb diets could have on gut health.

To sum it up, while some women may find benefits from a low carb or keto diet for PCOS, the risks may outweigh the benefits, especially since there are so many other ways to address PCOS.

Additional Support for PCOS

Support for PCOS takes a holistic approach. While diet is essential, you can’t ignore other aspects of health. You can sign up to get a copy of my free guide to balancing your hormones, and here are some of my top recommendations for PCOS management.

Choose Smart Carbs

You don’t have to go low carb to lose weight and support a healthier blood sugar balance. But you can be smart about your carbs. Choose complex carbs rich in fiber and health-promoting polyphenols like ancient grains and brightly colored fruits and vegetables. Unlike refined carbs (think sugar and white flour), complex carbs result in a more gradual blood sugar response than rapid spikes.

Also, pairing your carbs with protein or healthy fats helps manage blood sugar while keeping you satisfied longer after eating. And remember, cutting down on carbs is helpful; it just doesn’t have to be so drastic. Focus more on what you can add by filling your plate with plenty of non-starchy veggies, a protein with a smart serving of carbs. 

Get Some Zzzs

Sleep is critical for regulating your blood sugar and insulin response, and interestingly, many women with PCOS also have difficulty sleeping. A study examining PCOS and sleep disorders concluded that support for improved sleep should be emphasized as much as diet and exercise for PCOS management.

Sleep hygiene looks different for all of us. Some women do well with a wind-down routine that triggers the brain to start winding down. Also, make sure to examine your sleep environment, so it’s not too hot and dark and quiet enough. There are also sleep-supporting herbs and supplements to help with feelings of calm to help.

Move Your Body, But Not Too Much

Yes, it’s possible to exercise too much. Just like undernutrition, over-exercise stresses your body. Include more strength training to increase lean muscle while not overdoing the cardio. 

Short, high-intensity exercises can be beneficial so long as you minimize and don’t do it every day. Mix in some walking and yoga to allow for gentle rest and repair. 

Find Stress Resilience 

When you can’t avoid stress, you can work on stress resilience. Stress resilience means that despite financial, work, or social stressors, you can manage them effectively. Stress increases cortisol which impacts both hormone and blood sugar balance.

Stress resilience looks different for each person. Whether walking, journaling, asking for help, breathing work, or spending time outside, find what helps you reconnect and feel more grounded. 

Consider PCOS Supporting Supplements

There are several excellent supplement options to consider to support PCOS symptoms and address root causes like insulin resistance. Magnesium, inositol, and vitex are all examples that can add to your other lifestyle changes. You can read about supplements for PCOS in more detail here.

If you have PCOS, it’s tempting to consider a low carb diet. While it may help short-term for some women, keto or low carb diets won’t completely fix or cure PCOS. The best approach is to look at your lifestyle as a whole and make changes that not only make you feel good but can be sustained long term. 

Have you ever tried a low carb diet for PCOS? Please share your experience below. I love hearing your stories!

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About The Author

Dr. Jolene Brighten

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Dr. Jolene Brighten, NMD, is a women’s hormone expert and prominent leader in women’s medicine. As a licensed naturopathic physician who is board certified in naturopathic endocrinology, she takes an integrative approach in her clinical practice. A fierce patient advocate and completely dedicated to uncovering the root cause of hormonal imbalances, Dr. Brighten empowers women worldwide to take control of their health and their hormones. She is the best selling author of Beyond the Pill and Healing Your Body Naturally After Childbirth. Dr. Brighten is an international speaker, clinical educator, medical advisor within the tech community, and considered a leading authority on women’s health. She is a member of the MindBodyGreen Collective and a faculty member for the American Academy of Anti Aging Medicine. Her work has been featured in the New York Post, Forbes, Cosmopolitan, Huffington Post, Bustle, The Guardian, Sports Illustrated, Elle, and ABC News. Read more about me here.