Is Keto Good for PCOS? The Ketogenic Diet and PCOS

Polycystic Ovary Syndrome (PCOS) is a common endocrine disorder. Many have been searching for effective ways to manage the associated signs and symptoms. With ‘keto’ topping the charts for most Googled food-related topics in 2020, you might be considering if the ketogenic diet could be your path to better managing PCOS.

Naturally, this has led to curiosity about whether this low-carb diet could help improve symptoms of PCOS. But what does the evidence say?

Before you begin your journey, it’s crucial to weigh the ketosis-led nutritional regimen against the backdrop of hormonal balance and metabolic health that defines PCOS management.

Keep reading for more on PCOS and the keto diet.

Key Takeaways

  • The popularity of the ketogenic diet has sparked discussions on its role in managing PCOS symptoms.
  • It’s important to critically examine existing evidence on keto’s effectiveness specifically for PCOS management.
  • The ketogenic diet has many potential issues including problems with long-term adherence, its impact on gut health, the immediate side effects and the long term effects, plus its link to nutrient deficiencies and disordered eating behaviours.

What is the ketogenic diet?

The ketogenic diet is a high-fat diet and low-carbohydrate diet that shifts your body into a state of ketosis. During ketosis, your body relies on fat for energy, converting it into ketone bodies or ketones. This happens when we don’t consume carbohydrates, as the liver breaks down fat stores to produce energy. Generally, within the keto diet, the macronutrient split is 80% fat, moderate protein and low carbohydrate intake.

Foods Recommended on the Keto Diet:

  • Fats: Avocados, nuts, and seeds
  • Protein: Meat and fish
  • Low-carb vegetables: Leafy greens
  • Fruits: Berries in moderation

Foods to Limit on the Keto Diet:

  • Starchy grains
  • High-carb fruits
  • Foods rich in sugar

The main sources of fats can include; butter, avocados, nuts, seeds, oil etc. Fat consumption is encouraged from unsaturated fats. Unsaturated fats are found in avocados, fish, nuts and seeds for example. The rest of the diet comprises a small number of carbohydrates avoiding high-carbohydrate foods such as starchy grains.

Whilst popular, the ketogenic diet is commonly difficult to follow due to its restrictive nature. But what about the effect of keto on PCOS?

Keto Diet and PCOS: What Does the Evidence Say?

Polycystic ovarian syndrome is a hormonal disorder that impacts approximately 1 in 10 people assigned female at birth. Symptoms of PCOS include excessive hair growth, irregular periods, rapid weight gain and more.

PCOS is thought to be influenced by insulin resistance, excess androgen levels and chronic inflammation. Therefore to reduce symptoms and improve quality of life management should focus on reducing high blood sugar levels, lowering free testosterone levels and reducing low-grade inflammation.

As keto is one of many low-carb diets it is unsurprising that is being recommended for PCOS. But does the research back up this claim?

Data on the keto diet for PCOS is lacking. In particular, data is limited to the short term and studies are small. The theory behind keto for PCOS is that a low carbohydrate diet may help with insulin resistance; a common driver and symptom of PCOS.

One study investigated the impact of diet on PCOS symptoms in eleven people with PCOS. Carbohydrate intake was limited to 20g a day for 6 months. Over these 24 weeks, improved LH/FSH ratio, and improved insulin levels were seen. Only five people completed the study, which may indicate the challenging nature of the keto diet.

A study was conducted on 20 PCOS participants, of whom only 18 completed the 3-month study due to the restrictive nature of the diet. For those who did complete the study, improvements in the menstrual cycle, liver function, blood glucose levels and body weight were found. Interestingly, similarly to the study above, only fourteen people completed the study.

Whilst the results appear promising, it is important to point out that the studies were carried out on a very small number of participants over short periods. Further research on larger samples of individuals over longer periods is required to deem results conclusive.

7 things to consider before trying keto for PCOS

If you do want to engage in a keto diet for PCOS there are 7 essential things to consider before making this change. It is also key to speak to your healthcare provider to make sure you’re being safely supported if you do attempt this diet.

Sustainability of the diet

Keto may seem like a quick fix for PCOS symptom management; however, its restrictive nature may increase carbohydrate cravings and make long-term adherence challenging.

Ensuring a balanced diet that includes all food groups might be more practical for managing your PCOS symptoms.

Impact on gut health

A keto diet drastically limits carb intake, potentially leading to inadequate fibre consumption. Adequate fibre from a variety of sources supports gut health and helps manage blood glucose levels, making it an important factor in PCOS management.

Long-term effects may be damaging

Emerging research points towards the potential long-term health risks associated with following a ketogenic diet, such as increased heart disease risk and elevated LDL cholesterol, cautioning against its sustained use. We also don’t know the long-term effects on reproductive hormone levels.

Potential side effects

Expect side effects ranging from the mild “keto flu” to more serious implications like constipation due to low fibre intake, insomnia, dehydration, and an increased risk of bone fractures and kidney stones.

Unsuitable for pregnant people or those trying to get pregnant

A ketogenic diet is not recommended if you’re pregnant or trying to conceive due to the associated risks, including birth defects and gestational diabetes. Alternative, less restrictive diet choices are advisable during this time.

May cause nutrient deficiencies

The ketogenic diet’s restrictive nature can lead to a lack of essential nutrients. If you are not eating a wide range of fruits, vegetables and wholegrains you are likely to be at risk of being deficient in selenium, magnesium, phosphorous and vitamins B and C. Ensure you are getting a well-rounded intake of vitamins and minerals through food first, before through the use of supplements, to maintain overall health.

May lead to disordered eating behaviours

The keto diet’s stringent approach towards food can sometimes result in an unhealthy relationship with eating. We know that people with PCOS are at a higher risk of disordered eating behaviours and eating disorders such as binge eating disorder. Always speak to a professional if you are concerned about your relationship with food.

A Nutritionist’s Opinion: PCOS and the Keto Diet

As a PCOS Nutritionist, I do not recommend the keto diet for PCOS. To put it simply, limited data exists regarding the ketogenic diet’s long-term effects on PCOS and, in fact, it may result in poorer gut health and nutrient deficiencies. Whenever you are amending your diet seek a medical professional’s advice.

Frequently Asked Questions

We answer the most commonly asked questions about PCOS and the keto diet.

How does the ketogenic diet impact fertility for those with PCOS?

There is no evidence for the keto diet on fertility outcomes in people with PCOS. Keto is hypothesised to influence fertility in individuals with PCOS by potentially improving insulin sensitivity and reducing insulin levels but there are no clinical trials to back this up.

Can adhering to a keto diet exacerbate symptoms of PCOS?

For some, a keto diet could potentially exacerbate symptoms of PCOS and lead to poor outcomes like disordered eating, reduced gut health and nutrient deficiencies. 

What are the potential risks of a keto diet for individuals with PCOS?

Following a keto diet could lead to potential risks such as:

  • Nutrient deficiencies due to the restrictive nature of the diet.
  • Increased cholesterol levels owing to a high-fat intake.
  • Negative impacts on the gut microbiome given the low intake of fibre-rich foods.
  • Possible exacerbation of feelings of restrictiveness and food obsession, which may not be conducive to a healthy relationship with food.

How effective is a keto diet compared to a low-carb diet for weight loss in PCOS patients?

A ketogenic diet is a more restrictive version of a traditional low-carb diet. The keto diet has little to no evidence for its impact on PCOS patients and their symptoms.

Should individuals with PCOS follow a keto or paleo diet for better health outcomes?

There is little to no evidence for following a keto or paleo diet on PCOS symptoms. Choosing a way to eat depends on individual preferences and health goals.

Both diets restrict certain food groups and can lead to disordered eating behaviours. Consultation with healthcare professionals is advisable.

What is the best dietary approach to manage hormonal imbalances for those suffering from PCOS?

There’s no single dietary approach that guarantees the management of hormonal imbalances in PCOS. A balanced, varied diet rich in whole foods is generally recommended. Ensure you get enough fibre in your diet, and include foods rich in omega-3 like oily fish. Learn more about foods for PCOS here.

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Alex Okell ANutr Founder and Editor

Founder and Editor | Registered Associate Nutritionist


Founder of Be The Collective LTD [The PCOS Collective & The Endo Collective] Alex Okell ANutr is a London-based reproductive health nutritionist with experience in research, private practice and digital media. She holds a Master’s degree in Nutrition from King’s College London and has co-authored papers with the University of Cambridge, King’s College London, The Food Foundation and the Food Standards Agency. Alex offers 1:1 PCOS support in our virtual PCOS clinic.

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