Does a Ketogenic Diet work for PCOS? - Sepalika
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Does a Ketogenic Diet work for PCOS?

Aug 3, 2018

Many women of reproductive age suffer from a condition known as Polycystic Ovarian Syndrome (PCOS).  While the symptoms of PCOS usually do not cause actual pain, they do cause the emotional pain of infertility and can lead to additional health concerns.  PCOS is characterized mainly by polycystic ovaries, hyperandrogenism and anovulation.  PCOS affects around 4-10% of women of reproductive age.[i] [ii]

PCOS has no determined cause except that it could be genetic, but it has also been linked to obesity, insulin resistance and type-2 diabetes.  PCOS has no specific treatment or cure, but a variety of holistic treatments have been suggested.  One of these is a change in diet to a low carbohydrate diet like a ketogenic diet.

What Is the Keto Diet and How Does It Work?

Ketogenic Diet work for PCOS
What Is the Keto Diet and How Does It Work

The ketogenic diet is a low carbohydrate, high fat diet.  It drastically cuts carbohydrate in-take down to 20 net grams of carbohydrates per day and increases fat to about 75% of daily calories.  Unlike other low carbohydrate diets, it is not high protein.  The protein consumed should stay the same as on a regular diet, at around 20-25% of daily calories.

In a normal diet, people obtain energy primarily from carbohydrates.  In the body, these carbohydrates are broken down into glucose.  Glucose enters the bloodstream and is taken to cells for use as energy by insulin.  In some people, specifically those with insulin “resistance”, their body does not produce enough insulin to properly regulate glucose uptake by cells.

On a ketogenic diet, the body is no longer relying on glucose for energy.  The body relies on fat for energy.  The fat can come from fatty foods, or fat stores in the body.  When the fat is broken down, it eventually is broken down into ketones which cells use for energy.  This process is called ketosis.  Because the body is no longer taking in a lot of carbohydrates on the ketogenic diet, a person gets a chance to properly “re-sensitize” their body to glucose and insulin.

How Can Keto Help With PCOS

Ketogenic Diet work for PCOS
How Can Keto Help With PCOS

Many women who have PCOS have pre-diabetes or type-2 diabetes, including insulin resistance.   Some theorize that this insulin resistance could be the cause of high testosterone production and a bad Luteinizing Hormone and Follicle Stimulating Hormone (LH/FSH) ratio.[iii]  Other symptoms of PCOS include high cholesterol and high blood pressure.

As mentioned previously, the ketogenic diet has a well-known effect on the body’s insulin, which is a possible reason for why it helps sufferers of PCOS.  In one study on the ketogenic diet conducted specifically on women with PCOS, the symptoms of PCOS were drastically reduced – which the study theorized was due to insulin re-sensitization.

In the study, free testosterone levels were reduced, as were cholesterol levels, blood pressure and LH/FSH ratio was improved.  In addition, all of the women lost a significant amount of weight over the 6 months of the study.  Last but not least, 2 of the 5 women that were previously infertile conceived after the study!

The ketogenic diet is also well known at reducing chronic inflammation.  It does this through several mechanisms in the body, including reducing reactive oxygen species (ROS), limiting sugar (which causes inflammation in the stomach) and increasing ketones (beta-hydroxybutyrate) which help block inflammation.[iv]

Modifying Keto for PCOS

Ketogenic Diet work for PCOS
Modifying Keto for PCOS

The first step to properly starting a ketogenic diet is to calculate the macronutrients (fat, carbohydrates, protein, calories) needed for the diet that are specific to your body.  There are many calculator tools like this one available that consider personal attributes such as body weight, sex, height, and health factors.

Secondly, because a ketogenic diet is low carbohydrate, many people do not consume enough fiber (since fiber usually comes from carbohydrates).  However, this does not have to be the case.  There are many options of low carbohydrate vegetables that should be incorporated on a diet that will give a person enough fiber throughout the day.  Plus, avocados, a mainstay for keto, have about 13 grams of fiber – over half of the recommended amount for a 2000 calorie diet.

Vitamins and supplements are also an important factor to include on a ketogenic diet.  Many people fall short on potassium, calcium and magnesium.  While potassium needs to be obtained from food, calcium and magnesium can come from supplements or food.  Cheese and almonds are two foods that can be incorporated into a ketogenic diet to provide calcium and magnesium; while avocados and salmon provide a good amount of potassium.

Drinking plenty of water and supplementing with sodium is also important.  One of the side effects of a ketogenic diet is water loss due to glycogen depletion.  This can cause the body to also deplete sodium.  Drinking plenty of water and adding sodium to food is an easy and simple solution to this possible side effect.

The Downsides of Keto for PCOS


Ketogenic Diet work for PCOS
The Downsides of Keto for PCOS

Possible Weight Gain

While a ketogenic diet is often used for weight loss, if macronutrients and calories are not properly tracked, it can easily cause weight gain.  How you ask?   Because fat is extremely calorie dense compared to carbohydrates.  In only 1 tablespoon of butter is about 100 calories.  If you compared this to 1 tablespoon of any carbohydrate, it would a fraction of those calories.  Tracking meals and being aware of portion sizes is extremely important when starting a ketogenic diet.

Outside of this, a ketogenic diet is actually super helpful for weight loss.  It improves satiety and fullness hormones, while reducing hunger hormones.  It also improves fat utilization for energy, while decreasing fat storage.

Menstruation Irregularity

Drastically reducing carbohydrates can lead to period irregularity in some women.  Some women actually do need a certain amount of carbohydrates for menstruation, but the difficulty is that this amount is different for every person.  Some women may menstruate perfectly normal on the keto diet, while others may not at all.  If a person if very active, they may require more carbohydrates than someone who is not active.  You must be aware of your body and the changes incurred from a ketogenic diet.  Speaking to a nutritionist who is familiar with the ketogenic diet is highly recommended prior to beginning.

One option for very active women is carb cycling or a cyclical ketogenic diet.  Both of these involve the reintroduction of carbohydrates periodically, while the majority of the time sticking to a ketogenic diet.

On a cyclical ketogenic diet, carbs can be increased one or two days a week around high times of exercise.

For carb cycling, it is just the reintroduction of carbs a few days a week to a few days a month, not around times of exercise.

Again, speaking to a nutritionist familiar with keto is the best way to figure out what your body can handle, especially if your period becomes irregular after starting keto.


While more studies are needed to continue to prove the results of a ketogenic diet on PCOS, the initial studies are very encouraging.  Proper implementation is a necessity when starting the diet.  Speaking to a nutritionist and your physician is recommended prior to starting the diet.

Janine Einhellig
Janine Einhellig is owner and author at, a website focused on helping people achieve success on the ketogenic diet through information, meal plans and coaching.  Janine enjoys writing and operating Keto Domain because of the great impacts the ketogenic diet can have on quality of life.
Janine Einhellig

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