What Is Lean PCOS?

Delayed diagnosis and other unique challenges

Lean PCOS is polycystic ovary syndrome in people of normal weight. Up to 30% of women with the condition fall into this group. But since they are in the minority and excess weight is considered a classic symptom, those with lean PCOS may not be diagnosed right away.

Those who are lean with PCOS can face challenges, including fertility issues and a higher risk of undiagnosed diabetes and heart disease. Their increased levels of androgens (male hormones) can also lead to symptoms like acne, unwanted hair growth, and hair loss.

This article explains the unique challenges lean individuals with PCOS face. It also underscores how lifestyle and diet habits can help any person with PCOS improve their overall health.

A woman weight training and listen to music
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Delayed Diagnosis

PCOS is a condition in which cysts form on the ovaries. which can make conceiving a baby difficult and involve symptoms such as irregular menstrual cycles, acne, hirsutism (excess hair growth on the face and/or body), weight gain, and trouble sleeping. 

About one in 10 women of childbearing age have PCOS. The majority (about 70%) are overweight or obese, which helps to explain why much of the information on PCOS focuses on overweight women.

This means lean women with PCOS often go undiagnosed for years. Whereas overweight women with PCOS may be diagnosed while they are in high school, lean women with PCOS may not be diagnosed until they struggle to conceive a child.

The often-delayed PCOS diagnosis can have a domino effect, meaning that it can delay a finding of diabetes and heart disease, too.


Studies have found that 3% to 10% of lean women with PCOS have undiagnosed diabetes. This can happen because healthcare providers don’t generally expect adults of normal weight to develop diabetes or insulin resistance

This said, obese women with PCOS do have a higher risk for diabetes compared to women of normal weight with PCOS. To play it safe, some experts recommend that all women with PCOS get their insulin levels checked, regardless of their weight.

Heart Disease

Lean women with PCOS are more likely to have a delayed or missed diagnosis of heart disease. Researchers have compared the cholesterol levels of normal-weight women with PCOS to women without PCOS.

They found that the healthy-weight women with PCOS were more likely to have lower levels of “good” cholesterol (HDL) and higher levels of “bad” cholesterol (LDL). The bad type of cholesterol is known to clog arteries, sometimes leading to heart disease.

Insulin Resistance

Insulin resistance is usually linked with obesity, but women of normal weight with PCOS also have an increased risk of developing insulin resistance even though they're not overweight.

Researchers say that 20% to 25% of lean women (those with a body mass index under 25) are insulin-resistant.


The most commonly used measure to correlate weight and height is the body mass index (BMI). It uses weight and height to try and estimate body fat. The resulting number is then used to categorize people as underweight, normal weight, overweight, obese, or morbidly obese. BMI is not perfect, however, and does not account for other factors that determine body composition like age, muscle mass, or sex. BMI calculations may, for example, overestimate body fat in athletes or in older people. Additionally, BMI can also stigmatize and shame people who do not meet what is considered an ideal weight or body shape. 

The connection between insulin levels and PCOS is not fully understood. Women with PCOS are not the only ones who can be insulin-resistant despite having their weight fall into the normal range for their height.

A commonality appears to be abdominal obesity. This is when the abdominal area has more fat than it should.

Abdominal obesity is more common among people who are obese. But it can occur in those of a normal weight, too.

Calculate your waist-to-hip ratio to be sure. Women are more likely to have elevated levels of insulin if their waist-to-hip ratio is higher than 0.85.

Calculate Your Waist-to-Hip Ratio

  1. Without holding in your stomach, use a cloth measuring tape to measure the circumference of your waist where it is smallest.
  2. Measure your hips at the point where the circumference is largest. (This will probably be where your buttocks stick out the most.)
  3. Divide your waist measurement by your hip measurement.
  4. If you get 0.85 or higher, your risk of developing insulin resistance and other health problems related to obesity is higher. This is true even if your BMI falls in the normal or healthy range.

Fertility Treatment

Impaired fertility is one of the most consequential effects of PCOS. Women are often prescribed:

  • Clomid (clomiphene)
  • Femara (letrozole)
  • Glucophage (metformin)
  • Injectable fertility drugs if the above treatments aren't effective

The most common advice given to overweight women with PCOS wanting to get pregnant is to lose weight. For women who are obese, losing 5% to 10% of their current weight can make fertility drugs more effective.

However, this doesn’t apply to lean women with PCOS. They have much higher pregnancy rates with fertility treatments compared to their overweight peers.

Metformin is sometimes used to help women with PCOS conceive. Metformin is not a fertility drug. It’s actually intended for insulin resistance. But it can improve ovulation in women with PCOS. (Regular ovulation can improve the chance of conception.)

One study compared the effects of metformin on lean and obese women with PCOS. When treated with metformin, lean women with PCOS were twice as likely to see their regular menstruation and ovulation cycles return.

Being a woman of normal weight who has PCOS doesn’t mean you won’t struggle to conceive—or that fertility treatment is guaranteed. But you are more likely to have success compared to women who are overweight or obese with PCOS.

Lifestyle and Diet Solutions

Certain lifestyle and dietary habits can improve the overall health of lean women with PCOS, too.

Maintain Healthy Weight

It can be frustrating to develop PCOS despite maintaining a healthy weight and waist circumference. Still, maintaining that healthy weight is important for all women with PCOS. It can contribute to enjoying a healthier life.

Research has found that as women with PCOS get older, they are more likely to develop insulin resistance. This risk was lower among lean women. Put another way, maintaining your weight can help reduce your diabetes risk.

Resistance Exercise

Resistance exercise can bolster your weight management efforts. Progressive resistance exercise is weight training specifically intended to increase strength and muscle mass.

This is done by slowly increasing the weight being lifted or the repetitions being completed. (Some women are afraid that lifting weights will lead to them bulking up, but this is unlikely to happen.)

A study of lean women with PCOS found that adding resistance training helped:

  • Decrease visceral fat (the abdominal fat that increases your risk of insulin resistance)
  • Decrease elevated androgen levels
  • Improve menstrual and ovulatory irregularities
  • Increase lean muscle mass

The last element is especially important. Many dietitians believe that people with greater muscle mass get hungry less often, which can help with weight control.


Another potential way to improve your quality of life when living with PCOS is getting professional counseling, especially if you feel anxious or depressed.

People are available to help you—and they're one phone call away.

Call For Help

A Place of Hope specializes in helping people who are grappling with anxiety or depression. Call them at 1-888-771-5166.

For a referral to a mental health professional in your area, you can call the Substance Abuse and Mental Health Services Administration hotline at 1-877-726-4727. SAMHSA is a division of the U.S. Department of Health & Human Services.

What Should You Do?

If you have PCOS and you're at a normal weight, certain steps can keep you on track for good health:

  • Get your insulin and glucose levels tested. Your doctor may not think to test your blood sugar levels if you're not obese. But having PCOS puts you at risk for developing insulin resistance even if you're not overweight.
  • Maintain your healthy weight. Having PCOS makes it more difficult to maintain a healthy weight. But it's worth the effort.
  • Eat a healthy diet and avoid high-sugar foods. Eating well is vital to your health. This is true for all people, but especially for those with PCOS.
  • Begin resistance training. A regular exercise routine is a good idea. But make sure your exercise routine includes resistance training. This will increase your lean muscle while reducing the "bad fat" in your body.
  • Reach out for emotional support. Women with PCOS are more likely to struggle with anxiety and depression. Reach out for support from friends and professionals.
  • Advocate for yourself when you see your doctor. Get a second opinion if you feel your doctor isn't giving you the care you need.


Since most women with PCOS are overweight or obese, lean women with PCOS may be overlooked. This can spell trouble by leading to a delayed diagnosis of problems like diabetes, heart disease, and insulin resistance. The best thing lean women with PCOS can do is to maintain a healthy weight. Following a healthy diet can help, too.

A Word From Verywell

It can be frustrating to be diagnosed with PCOS and find that most of the information on the topic is aimed at overweight women. Your frustration may be compounded by those who are doubtful about your diagnosis because you're not obese.

While obesity is a risk factor for PCOS, about 20% of women with PCOS have a weight and waist circumference that falls within a healthy range. But fear not: You are not invisible. Just be sure not to behave as if you are. You have to remain proactive about managing your PCOS.

Frequently Asked Questions

  • How is PCOS diagnosed?

    PCOS diagnosis involves a physical exam, bloodwork to test hormone levels and to see if the patient is ovulating, and imaging tests. Healthcare providers sometimes perform an endometrial biopsy to check for endometrial cancer, which is more common in those with PCOS.

  • Will a lean person with PCOS experience similar symptoms to someone who is not lean and has PCOS?

    Yes, a lean woman may experience similar symptoms. These symptoms include unwanted body hair, irregular or missed periods, and insulin resistance.

  • How common is PCOS?

    It's fairly common. It affects between 6% and 12% of all women in the U.S.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Goyal M, Dawood AS. Debates regarding lean patients with polycystic ovary syndrome: A narrative reviewJ Hum Reprod Sci. 2017;10(3):154‐161. doi:10.4103/jhrs.JHRS_77_17

  3. Pelanis R, Mellembakken JR, Sundström-Poromaa I, et al. The prevalence of Type 2 diabetes is not increased in normal-weight women with PCOS. Hum Reprod. 2017;32(11):2279-2286. doi:10.1093/humrep/dex294

  4. Marshall JC, Dunaif A. Should all women with PCOS be treated for insulin resistance? Fertil Steril. 2012;97(1):18–22. doi:10.1016/j.fertnstert.2011.11.036

  5. Cho WK, Kim H, Lee HY, et al. Insulin resistance of normal weight central obese adolescents in Korea stratified by waist to height ratio: results from the Korea National Health and Nutrition Examination surveys 2008-2010Int J Endocrinol. 2015;2015:158758. doi:10.1155/2015/158758

  6. Nicholson F, Rolland C, Broom J, Love J. Effectiveness of long-term (twelve months) nonsurgical weight loss interventions for obese women with polycystic ovary syndrome: a systematic reviewInt J Womens Health. 2010;2:393–399. doi:10.2147/IJWH.S13456

  7. Kogure GS, Miranda-Furtado CL, Silva RC, et al. Resistance exercise impacts lean muscle mass in women with polycystic ovary syndrome. Med Sci Sports Exerc. 2016;48(4):589-98. doi:10.1249/MSS.0000000000000822

  8. American Cancer Society. Endometrial cancer risk factors.

  9. Centers for Disease Control and Prevention. PCOS (polycystic ovary syndrome) and diabetes.

By Rachel Gurevich, RN
Rachel Gurevich is a fertility advocate, and recipient of The Hope Award for Achievement, from Resolve: The National Infertility Association. She is the author of "The Doula Advantage" and "Birth Plans for Dummies," and a member of the Association for Health Care Journalists. She has contributed to Reuters Health, USA Today, and more.