Insulin resistance is by far the most common root cause of PCOS.
At least 80% of Cysters have some level of insulin resistance, including those who don’t have excess body weight (often referred to as “lean PCOS”).
Weight gain is only one symptom of insulin resistance, and it doesn’t happen for all Insulin-Resistant PCOS Cysters.
If you’ve been told you don’t have a problem with insulin because you’re not overweight, you might be missing out on the correct treatment for your PCOS.
When researchers used the most sensitive insulin resistance tests to compare women with and without PCOS (controls), they found an interesting difference.
75% of lean women with PCOS had insulin resistance compared with only 24% of lean women controls.
The same study found insulin resistance in 95% of overweight women with PCOS, compared with only 62% of overweight controls.
This study reveals that the insulin resistance associated with PCOS is independent of weight gain.
In other words, weight gain isn’t the cause of insulin resistance in PCOS.
In fact, the opposite is true – insulin resistance is often the cause of weight gain.
If you aren’t overweight, there is still a significant chance that insulin resistance is driving your symptoms.
PCOS significantly increases our chances of having issues with insulin, regardless of weight.
Insulin resistance happens when our cells become “deaf” to the signals of insulin telling them to open up and let sugar from our blood inside for storage.
Insulin is like a key that fits into the lock on the cell door.
In insulin resistance, this key has become a little rusty, and it takes a lot of fiddling to get the door open.
This extra time taken to open the cell door means that insulin stays raised in the blood for a lot longer than it should.
If you have high levels of insulin for a long time, it triggers your ovaries to start producing extra testosterone and other androgens.
Excess insulin also lowers an important protein called sex hormone binding globulin (SHBG).
I like to think of SHBG as a hormone sponge. Its main role is to mop up excess hormones and keep levels balanced. When you have higher levels of androgens floating around, combined with lower SHBG, it’s a recipe for disaster.
Instead of being mopped up, the androgens run free and get into your scalp hair follicles, killing them and making them fall out.
They get into the pores in your skin, clogging them and causing acne.
And they get into your face and chest hair follicles and change your unnoticable baby hairs into thick, coarse, black hairs.
To make matters worse, high testosterone levels trigger even more insulin production, creating a frustrating spiral where androgen levels continue to rise.
High insulin also causes your brain to secrete less follicle stimulating hormone (FSH). FSH is needed to trigger your follicles (baby eggs) to grow to the right size needed for you to ovulate.
Without enough FSH, you either fail to ovulate altogether (meaning your period disappears) or it takes much longer to ovulate (causing very long gaps between periods).
Finally, high insulin levels cause another key hormone involved with ovulation, luteinizing hormone (LH), to be secreted in high levels.
In the right amounts, LH is needed to trigger ovulation. When levels are too high, your body shuts down or delays ovulation, further contributing to missing or irregular periods.
Take the quiz below to rate the likelihood of insulin being a root cause of your PCOS.
Each time you answer yes, give yourself one point.
If you said yes to four or more of the points above, there’s a high chance insulin resistance is the root cause of your PCOS.
If you aren’t sure or would like to confirm this with testing, see below for the best tests to diagnose insulin resistance. Testing is optional.
You might not know if you have insulin resistance because your doctor didn’t order the most sensitive tests.
The most commonly used tests are fasting glucose and HbA1C.
These tests are unfortunately not sensitive enough to pick up on early stage insulin resistance, and are better at diagnosing severe insulin resistance like that in type 2 diabetes.
A 2014 study found that HbA1C missed 45% of people with type 2 diabetes, which is a more severe form of insulin resistance.
This means that this test has a high likelihood of missing early stage insulin resistance.
Fasting blood glucose is another commonly used test, however the upper “normal” limits set by most pathology laboratories are likely far too high.
The commonly accepted upper limit for fasting blood glucose is 100mg/dL (meaning that a number below 100 is considered normal).
A 2005 study showed that people with fasting blood glucose levels between 91-99mg/dL went on to develop type 2 diabetes.
If you’ve ever had an oral glucose tolerance test before (OGTT), you likely haven’t forgotten it!
This test involves drinking a sickly sweet drink and having your blood taken every hour for two to three hours to measure the rise and fall in your glucose levels.
It’s commonly used in pregnancy to diagnose gestational diabetes.
Whilst more accurate than the two previous tests, an OGTT also won’t pick up the early stages of insulin resistance because it measures glucose rather than insulin.
An interesting study showed that OGTTs missed up to 50% of people with diabetes.
The reason that blood glucose is often normal in insulin resistance is because your insulin is being secreted at incredibly high amounts in order to keep glucose low.
This means that when all we look at is your glucose levels, they appear normal.
However, behind the scenes, your insulin is working overtime to keep glucose balanced.
Only testing glucose means you could miss out on the correct diagnosis and treatment for your PCOS.
If your doctor has ruled out insulin resistance by testing your fasting blood glucose, HbA1C, or OGTT and you feel it could still be an issue for you, don’t be afraid to ask for further testing.
I’ve covered the best tests to ask for below.
The most accurate test for insulin resistance is a Glucose Tolerance with Insulin Assay.
This is similar to an OGTT, but measures insulin as well as glucose.
You will have your blood taken fasting and then at one and two hour intervals after drinking a glucose drink.
This test has been shown to be 75% more effective at detecting diabetes and pre-diabetes than the traditional OGTT.
Ideally, your fasting insulin should be less than 10mlU/L (60pmol/L).
At the one- and two-hour marks after your sugar drink, your insulin should be less than 60mlU/L (410pmol/L).
If it’s higher than this, it indicates insulin resistance is a problem for you.
This test is far less common than a standard OGTT, fasting glucose, or HbA1C, so don’t be surprised if your doctor hasn’t heard of it.
Keep asking or find a new practitioner who can support you to get access to the right testing to rule in or out insulin resistance.
Insulin resistance can cause weight to be deposited around your mid section. The higher your waist circumference is, the more likely you are to have insulin resistance.
Grab out your tape measure and place it at the top of your hip bone. Then bring the tape measure around your body in line with your belly button.
Make sure it’s straight and even. Take a breath in and out and relax your belly (make sure you’re not holding it in).
Check the number on the tape measure. For women, a measurement of 80cm (32 inches) indicates a higher likelihood of insulin resistance.
The risk increases the further above 80cm your waist measurement is.
Remember that there is a misconception that being overweight causes insulin resistance.
This means that you don’t have to have a high waist measurement or be overweight to have insulin resistance – it just increases your chances.
The signs and symptoms listed above also give us a clear indication of whether insulin is a problem for you.
If you are overweight or have been diagnosed with insulin resistance, there’s a good chance you’ve been offered Metformin – the leading insulin-sensitizing drug.
Metformin helps to improve your body’s sensitivity to insulin and can be really helpful in treating this root cause for some women.
Unfortunately, this drug is associated with a high rate of side effects –more than 50% of women report gastrointestinal side effects (nausea, diarrhea, and vomiting).
Metformin is also well known to cause vitamin B12 deficiency, so if you are using this drug to manage your insulin levels, I highly recommend a daily B12 supplement to combat this.
Whether or not to use Metformin for your PCOS is a personal choice. You can achieve the same results – if not better – as Metformin by following the diet and lifestyle changes in this post.
If you are noticing side effects from Metformin and would like to try an alternative, inositol has been shown head-to-head against Metformin to achieve higher success in weight loss, restoring regular ovulation and natural pregnancy, without the side effects.
"Changing what you eat, how you move and which supplements you take is the most effective way to reverse insulin resistance and thrive with PCOS."
If you find you are getting hungry, try increasing your healthy fat source and opt for solid forms of fat like avocado, nuts, and seeds rather than oils.
These are often more satiating because they take up more room in your stomach.
"Once we get your insulin functioning better, you won’t have intense cravings anymore and you’ll find you can easily maintain your energy levels and focus throughout the day."
For the next four weeks, your goal is to cut all sweet drinks (sodas, flavored milks, mixers), added sugar, and dessert foods out of your diet.
This isn’t forever – it’s just for four weeks while we reset your blood sugar and insulin levels.
This includes “natural” sugars like those in paleo desserts, bliss balls, and other treats that use dried fruit, agave, or coconut sugar.
It also includes sweetened yogurt, granola bars, and protein bars.
You can still enjoy one or two serves of whole fruit paired with protein or healthy fat.
If you need a sweetener while you are adjusting, try stevia or monk fruit as these are natural sweeteners that won’t spike your blood sugar levels.
You can also enjoy one to two squares of 85% or higher cacao chocolate as this is naturally very low in sugar.
While you are completing these four weeks, make sure you are having full, sustaining meals and snacks with plenty of protein.
This will help to keep you feeling satisfied and reduce cravings for sugar.
Remember that once we have reversed your insulin resistance, you won’t have cravings for sugar anymore.
To help make quitting sugar easier, I’ve put together a bonus resource for you: Kick Your Sugar Cravings. There, I’ve covered many more tips to make this transition easier.
After the four weeks are up, you can test your body’s response to small amounts of sugar.
I suggest enjoying one dessert or sweet food once or twice a week and really savoring the experience.
Pick the day you are going to have a sweet treat and choose what you will make or buy.
When you are ready to enjoy your sweet, sit without distractions and really be present while you eat it.
Being mindful will reduce cravings for more sugar.
Once your insulin is functioning normally again, you can adopt the 80/20 rule.
This means enjoying a balanced, sugar-free diet 80% of the time, and choosing special occasions to enjoy small amounts of sugar or other foods that are less helpful for insulin.
Having insulin resistance now means you will always have a tendency to develop it again even after you have reversed it following the principles in this post.
Finding a long-term, sustainable way to keep up these habits without feeling deprived is what will make all the difference to your symptoms.
Experiment with the 80/20 rule and find what works best for you.
Ultimately, we want the PCOS Repair Protocol to form the habits you will follow for the rest of your life, instead of being another diet that you ditch for your old ways of eating after a few weeks because you felt unsatisfied or deprived.