Is the Ketogenic Diet right for your PCOS?

First, it is important for me to explain as a Registered Dietitian, that there is not one PCOS, therefore there is not one best diet to treat it.

Since PCOS is a syndrome, we may have several side effects such as high androgens, missing periods, cysts on our ovaries, which all have different underlying root causes. One of the main causes, though, can be insulin resistance...but it can also be stress, so it is important to figure out what is impacting you the most before considering the Ketogenic diet.

50% of women with PCOS have high stress hormones, DHEA-S levels. For these women, a low carb diet would put more stress on their adrenal glands and potentially result in worsening symptoms. But for some women with PCOS – especially those with insulin resistance and obesity – a ketogenic diet can work really well.

A few weeks ago, I saw a patient who booked a consultation to discuss her struggle with weight and fatigue due to PCOS. She explained that she cut back on calories and started Metformin, but still is unable to lose the weight.

“But I’m following all the low GI recommended for PCOS, so how can it not work?”

As we reviewed her blood test results, I showed her the tests that were indicating that she had severe insulin resistance.  I explained that this meant that her hormone insulin, like a key, could not fit into the lock on our cells to open it up and let the glucose in, so her body was effectively not able to use any of the carbohydrates she was eating (even if they were ‘slow release’ low GI carbs). 

So if a low glycemic index diet doesn’t work for someone who’s severely insulin resistant, what does?


A Ketogenic diet.


A keto diet is a very low carbohydrate diet.  The keto diet changes the “fuel” that our body uses for energy. Severely restricting sugars (carbohydrates) from our diet forces your body to run off the fuel provided by our stored body fat. 

My client's body wasn’t able to use the carbohydrates she was eating as her insulin ‘key’ couldn’t open up the ‘lock’ on the cell, so instead she was storing those carbs as fat and getting more tired in the process!


So by turning her body into fat burning mode means that she could now use some of her own fat for energy and as she was eating very little carbohydrate, she wasn’t storing any more fat. 


But this doesn’t mean that a keto diet is right for all women with PCOS, or even all women with PCOS insulin resistance. And I also didn’t recommend that my client should do this long term- only until  she’d reversed her insulin resistance.

If you do try the keto diet then I recommend cycling in and out of it. This might mean that you stay on a keto diet for 3-6 months, then add some starchy carbs back in for 1 month to feed your gut bacteria.