Is the Keto diet right for PCOS?

This is one of the most common questions I get as a Functional Medicine practitioner and person with PCOS myself…

And with good reason! The Keto Diet is often touted as a solution for two of the biggest issues people with PCOS face: blood sugar issues and weight gain.

But as with most things related to PCOS, using the Keto diet for PCOS is not a one-size-fits-all solution. 

Today, let’s take a deeper look at this question – and hopefully, provide you with a customized answer. 


What Is PCOS?

If you’re reading this, you probably either have been diagnosed with or suspect PCOS: polycystic ovarian syndrome. 

But even though it’s very common (affecting 1 out of very 10 women), this condition is hugely misunderstood, so I think it’s always good to start with a quick refresher on what exactly it is.

First of all, despite what the name implies, people with PCOS don’t necessarily have cysts on their ovaries. (And equally important – just having cysts on the ovaries doesn’t mean you have PCOS!) Instead, PCOS is about hormone imbalance – specifically, an excess level of androgens. 

Androgens are hormones typically thought of as “male”: primarily testosterone and androstenedione, but also DHT, DHEA and DHEA-S. (But just to confuse things even further, some people with PCOS will never show high testosterone or DHEA levels.)

Along with androgen excess, people with PCOS generally have “ovulatory dysfunction” – meaning they don’t ovulate monthly. They may have irregular periods (long, short, heavy, or absent) – but they can also have normal-appearing periods (they might not even know they aren’t ovulating, or they may ovulate sometimes, and not others).

Lots of other symptoms go along with androgen excess and ovulatory dysfunction – but none of these HAVE to be present. Some people with PCOS have them all, and some have none:

  • Insulin resistance (even if the person is not overweight)
  • Cysts on the ovaries
  • Excess hair growth on the body
  • Weight gain and weight loss resistance
  • Acne
  • Thinning hair on the head
  • Oily skin or hair
  • Infertility


What Is The Keto Diet?

Now that we’ve brushed up on PCOS, let’s do the same for Keto.

Keto is shorthand for the ketogenic diet – this is a pattern of eating where carbs are kept low enough, and fat intake is increased, so that the body shifts from burning glucose (sugar, carbs) for fuel to manufacturing ketones, an alternative source of fuel for your body. The state in which you are using ketones for fuel is called “ketosis.”

It takes a few days of very low carb eating to switch into ketosis – and once you’re there, eating carbs again will bump you back out. That means keto is not a diet you can do halfway or dabble in easily – it’s all or nothing.

It varies person to person, but usually carbs need to be kept below 20-50 grams per day to achieve ketosis. That is very low: one banana alone has 27 grams of carbs. This means all starchy foods are out: potatoes, most fruit, oatmeal, rice, bread, etc. Non-starchy foods that are high in sugar – like ice cream – are also out.

But it’s not just about cutting carbs – you also have to significantly increase fat intake, with 70% or more of total calories coming from fat – and that’s where this can get a little tricky for some people (more on that to come).

But one REALLY important thing to note before we go any further: keto is not the same as just cutting carbs, and for people with PCOS, it should not involve under-eating. Under-eating calorically can further suppress ovulation, making PCOS symptoms worse. 


How Does Keto Help PCOS?

Keto may help PCOS by addressing one of the biggest symptoms: insulin resistance. And for people with PCOS who have weight loss as a concern, the keto diet may help them shed unwanted weight. 

Research has shown that in small groups of people with PCOS, a keto diet can:

  • Lead to weight loss
  • Normalize insulin levels and reverse insulin resistance
  • And, most importantly: The LH/FSH ratio, LH total and free testosterone, and DHEAS blood levels were also significantly reduced

That suggests that the Keto diet isn’t just treating the symptoms – it may actually help to balance hormone levels. 

It’s not completely understood yet how this happens, but the endocrine system is very complex, and interactions between hormones matter – and don’t forget that insulin is a hormone, too!

I know it sounds great, but before you dive into keto there is a big catch that we need to talk about. 


The Keto Diet for PCOS is NOT One-Size-Fits-All

If you are considering trying a keto diet for PCOS – great! I support you 100%. For my own PCOS, reducing carbohydrate intake was one of the best things I did.

But before you go any further…. I want to give you a quick warning:

Depending on your genetics, you might need to do keto a specific way.

Most people with PCOS need to follow a “Mediterranean keto” diet – in fact, it was this specific diet that led to the amazing results in that 2020 research article I mentioned above.

Mediterranean keto focuses on poly and monounsaturated fats from foods like olive oil, avocados, fatty fish, and nuts and seeds. 

Traditional keto focuses more on quantity than quality – it’s all about lowering carbs and increasing fat in any way possible.

That often means LOTS of cheese and red meat – both of which are very high in saturated fat. 

For some people, there is nothing wrong with saturated fat – they are genetically programmed to tolerate high levels of saturated fat well. But for many people – especially those with PCOS – saturated fat is problematic. 


3 Things People with PCOS Need to Know Before Starting Keto

There are two gene variants to look for and one general rule to know about before starting keto. 

First, for people with either the FTO or APOA2 SNP variant, saturated fat can be problematic. People with the FTO variant usually don’t tolerate simple sugars or saturated fats well. This variant also makes you more likely to burn fat slowly and struggle with feeling full. 

The APOA2 gene variant also affects metabolic hormones. Research suggests that people with this variant do best if they eat under 22 grams of saturated fat a day. That’s very hard to do if you’re eating red meat, dairy, and bacon!

Finally, dairy in particular can be a problem for people with PCOS – whether or not they have the FTO or APOA2 variants. Milk (from cows, goats, sheep, and camels) contains the hormone insulin-like growth factor-1 (IGF-1), which mimics insulin in our body. IGF-1 is a growth hormone (which makes sense, as milk is for baby animals!). In most people, a little dairy here and there can be well-tolerated because humans have a binding protein for IGF-1 that inactivates it

But for people with PCOS or hormonal imbalance, who already are likely to be insulin-resistant or have high insulin, the added burden of IGF-1 can be a problem. This is amplified because women with PCOS have LESS of the binding protein for IGF-1 and higher IGF-a levels than other people do, too. And the ovaries of women with PCOS are more sensitive to IGF-1 (and other growth hormones), too. 

IGF-1 can also cause your ovaries to overproduce testosterone (an androgen) – which is something we’re trying to minimize. 

That’s why I recommend most people with PCOS try cutting dairy – and if you’re considering Keto, get some basic genetic testing done to reveal how you tolerate saturated fat (I can help with that). 


Your Genes Can Reveal So Much

Whatever your health struggles are – I think investing in genetic testing is one of the smartest choices you can make. 

Your genes are like your body’s instruction manual. Your genetic variants can give you information about your diet, lifestyle, exercise needs – and even what nutrients you’re likely to struggle getting enough of. 

That’s why I’m making genetic counseling a bigger part of my practice: it helps patients create a truly customized health plan, without wasting time on plans that would never work for you genetically.

Want to learn more? Book a free consult with my team today and we can talk through what we offer. We’d love to support you on the journey to better health.