Here's the deal: not all women with polycystic ovary syndrome are overweight or obese – some of us are lean, even underweight.
Yes, obesity is a hallmark of polycystic ovary syndrome. But you can be skinny and have PCOS - up to 30% of women with polycystic ovary syndrome have lean PCOS.
Even though you don't have to gain weight to have PCOS, research suggests that you can still have high insulin levels. You're also more likely to have trouble getting pregnant and develop insulin resistance compared to women without PCOS.
Understanding that you have lean PCOS is important, because you'll need a customised treatment plan. The Frontiers in Endocrinology reports if you’re thin and have PCOS, you may respond differently to treatment.
Below, we'll explore the link between lean PCOS and infertility, plus treatment options.
What is Lean PCOS?
Lean PCOS is a type of PCOS without obesity. Unlike other types of PCOS, women with lean PCOS may be lean or only slightly overweight.
However, like overweight women with PCOS, lean women can also have irregular periods, excess androgens, and multiple cysts on their ovaries. And many of these symptoms may be tied to insulin resistance.
According to research published in Endocrine Connections, PCOS and weight gain are often associated with each other. Because of this connection, you might come across several articles helping women with PCOS to lose weight.
Although weight gain isn't officially part of the Rotterdam criteria - the criteria medical professionals use to diagnose PCOS - the majority of women with polycystic ovary syndrome are classified as obese.
“Up to 80% of PCOS patients are obese, and obesity is associated with a wide range of adverse events, many of which are closely associated with outcomes seen in PCOS literature. This makes obesity the quintessential confounder in the study of PCOS.
The authors add that there is a growing area interest in women who have PCOS and maintain a healthy weight.
“Recently, a subpopulation of PCOS patients, that is, not obese, coined ‘lean PCOS’, has elicited interest among researchers. This group comprises 20–30% of the PCOS population and provides the opportunity to look at PCOS independent of obesity.”
A team of researchers from Italy and the United States found that even in countries with high rates of obesity, a significant proportion of women with PCOS are still lean - at least one-third of them.
Despite being thin, these women are still susceptible to the health problems linked with PCOS. The 2022 Indian Journal of Endocrinology and Metabolism found women with lean PCOS had elevated insulin levels when compared to women without PCOS.
What’s more because PCOS is strongly associated with weight gain, women with lean PCOS may take even longer to get a diagnosis.
I remember this one time when one gynecologist took a look at me and stated that I only had polycystic ovaries (PCO) and not PCOS. Fortunately, by that time, I had already been diagnosed with PCOS over a decade ago. Then came the COVID lockdown and I managed to pack on 13kg. Possibly due to a poor diet and high levels of stress, my PCOS type may have worsened. You can read more about the different PCOS phenotypes in this article.
Even though I was skinny with PCOS, I had several other symptoms, including acne and excess body hair. Moreoever, I had a typical PCOS body shape, carrying extra body fat around my middle.
![](https://cdn.prod.website-files.com/61fa4f7472c9b274b1f2c338/64281ae60cb3c8202682189c_Lean%20PCOS%20example.jpeg)
Higher levels of testosterone can effect fat distribution, and you may find you have excess abdominal fat, instead of storing body fat around the hips or butt.
Doctor after doctor prescribed birth control pills, but these only provided short-term relief and didn't address the hormonal imbalance at the root of my symptoms.
If you have PCOS symptoms but you’re underweight, check in with a professional. Take this PCOS test.
Does lean PCOS cause infertility?
Lean PCOS can lead to infertility.
One analysis conducted by researchers from the United Kingdom showed that PCOS is the most common cause of anovulatory infertility. In addition, up to 95% of women with anovulatory infertility being treated at fertility clinics have PCOS.
Anovulatory infertility is when a woman doesn't ovulate regularly or at all. This means that the ovaries don't release an egg during a menstrual cycle, which may make it difficult to get pregnant.
If you have PCOS, your ovaries may produce too much testosterone and this can mess with ovulation.
An animal study showed high testosterone levels could make it more difficult for a fertilised egg to implant properly.
However, if you have lean PCOS, you might be less likely to experience evaluation than if you're overweight. Some experts suggest that women who carry more weight may not respond as well to ovulation medication. But, researchers admit, there's not enough evidence to fully back this theory up.
Treatment for Lean PCOS
If you're dealing with lean PCOS, your treatment plan might include prescription medication, supplements, dietary changes, and lifestyle tweaks. And, if you're still having trouble conceiving, assisted reproductive technology could come into play, too, according to this paper.
Diet
Excessive weight gain can worsen symptoms, but if you're already at a normal weight, you'll need to prioritise eating a PCOS-friendly diet. Losing weight might not be a
Instead, you'll want to adopt a healthy diet high in lean proteins, complex carbohydrates, and plenty of fiber. This way of eating can help manage hormone levels.
A review of the research published the 2021 Metabolism Open said while there was no consensus on one, single best diet for PCOS, diets that reduce insulin resistance and are low in simple sugars and refined carbohydrates were recommended by research. Since PCOS is associated with chronic inflammation, anti-inflammatory diets like the Mediterranean diet were also recommended. The authors of the paper make an important point: because you've got lean PCOS , you should focus on consuming enough essential nutrients, minerals, and vitamins. You don’t need to lose weight or cut back on eating.
The Mediterranean diet is rich in plant-based foods like fruits, veggies, whole grains, legumes, and nuts. You can also enjoy moderate amounts of fish, poultry, and dairy products, but you'll need to cut back on red meat and sweets.
Olive oil is used liberally, while the diet favours herbs and spaces over salt. There’s a ton of evidence supporting the health benefits of this way of eating.
It’s been shown to protect against heart disease, stroke, and certain cancers. Following a Mediterranean diet may even improve brain function and help you live longer.
Medication
Medication such as Metformin may be prescribed to manage insulin resistance, which is a common trait among women with PCOS.
An analysis published in the Journal of diabetes and metabolic disorders, found metformin treatment for fertility was more successful among women with lean PCOS than in those who were overweight. Metformin helped restore menstruation in 55% of lean women with PCOS, and induced ovulation in 45% of them.
Supplements
Supplements may also be recommended, such as Vitamin D and inositol, which can improve fertility and metabolic function.
Research suggests vitamin D can improve fertility in PCOS.
“...vitamin D supplementation may improve reproductive function in women with PCOS by restoring regular menstrual cycles [61,62]. There is a need for more randomized trials in well-delineated and determined populations that will help in defining the role of vitamin D in PCOS.”
If you're struggling with fertility due to polycystic ovary syndrome, you might also want to give inositol a try. Research shows inositol can improve insulin resistance, reduce androgen levels, and promote ovulation in women with PCOS. And all of these can boost your chances of getting pregnant.
Some research even suggests that myo-inositol, one form of inositol, may improve the outcome of assisted reproductive treatments among women with PCOS, but more research is needed.
Assisted reproductive technologies
If you're struggling with infertility due to polycystic ovary syndrome, assisted reproductive technology may be a the right option for you.
In vitro fertilization (IVF) is one of the most common fertility treatments. And other treatments include intrauterine insemination and ovulation induction. Both of these procedures involve using medications to boost your chances of ovulation.
Research shows women with PCOS have more success with assisted reproductive technology.
“BMI appears to have a marked effect on in vitro fertilisation (IVF) outcomes.”
Additionally, lifestyle changes such as regular exercise and stress reduction techniques may also be recommended.. By working with a medical professional, women with lean PCOS can find effective treatment options to manage their symptoms and improve overall health.
Create a personalised lean PCOS treatment plan
As you’ve seen, skinny people can have PCOS.
Honestly, dealing with lean PCOS can be tough, but don't worry - there are a ton of treatments out there that can help manage your PCOS symptoms.
One popular option is trying out a low-carb diet, since insulin resistance is a pretty common issue for folks with lean PCOS. Even if you're at a healthy weight, eating a diet rich in minimally processed, nutrient-dense foods will do wonders for your overall health.
Consider adding some supplements to your routine to bring your hormones into balance.
Definitely reach out to your doctor to come up with a plan that makes sense for your unique situation.
Importantly, listen to your body along the way - sometimes, you might need to adjust your treatment plan as you go to make sure you're getting the best results possible.