Why Weight Loss Isn’t the Whole Answer for PCOS

“Just lose weight.” For many women with polycystic ovary syndrome (PCOS), that is the first – and often only – advice they hear at every appointment. It can feel repetitive, frustrating and discouraging, especially when symptoms persist despite diet and exercise efforts.

PCOS affects ~1 in 10 women of reproductive age, making it one of the most common endocrine disorders in women worldwide. Yet awareness among clinicians varies, and standard care has long emphasized weight as the primary lever for symptom management.

“Misunderstandings about the cause of PCOS lead to ineffective treatments,” said endocrinologist Dr. Sherman J. Silber, the medical director of the Infertility Center of St. Louis at St. Luke's Hospital, who specializes in the field of reproductive medicine.

Silber and women’s health researcher Dr. Tessa Copp, a research fellow at the University of Sydney, spoke with Technology Networks to discuss how this framing can miss the real drivers of PCOS and perpetuate stigma.

This article explores why the weight-centric model is outdated, examines evidence on how PCOS develops and highlights emerging treatment approaches that prioritize hormonal, metabolic and psychological well-being over the scale.

What the evidence really says about weight and PCOS

In clinical practice, weight loss is often recommended as a primary treatment for women with PCOS. This approach is deeply embedded in most guidelines and general practice consultations.

“Optimizing a healthy lifestyle is first-line management for women with PCOS, as even small amounts of weight loss have been associated with improvements/reductions in symptoms,” said Copp.

“Although women with PCOS report difficulty losing weight and perceive a greater susceptibility to weight gain, weight management interventions have found that women with and without PCOS can lose the same amount of weight,” she added.

This weight-centric approach stems from the understanding that excess adiposity can exacerbate insulin resistance and elevate androgen levels, both of which are central to PCOS pathophysiology. However, while modest weight loss (5–10%) can lead to short-term improvements in ovulation and reduced androgen levels, these benefits often diminish over time. Studies indicate that most patients regain weight within a few years, and many continue to experience symptoms such as acne or hirsutism, even after weight loss.

“There is a big misunderstanding that only obese women have PCOS. But in fact, most women we see who have PCOS are not obese or even overweight. One thing all women with PCOS have in common is that they were simply born with too many eggs,” said Silber.

Symptoms improve only temporarily when weight is targeted, because weight is not the underlying problem.

“PCOS patients are not ovulating, which causes high levels of testosterone that increase their appetite,” he added. The hormonal imbalance drives fat storage and contributes to metabolic syndrome, hirsutism and oily skin.

“PCOS can be aggravated by being overweight, because fat cells absorb and then secrete estrogen, which makes PCOS worse since estrogen also suppresses gonadotropin. This is why you can lose weight and make your cycles more regular, but weight is not the essential feature of PCOS,” said Silber.

“PCOS is caused by too many eggs, not by being overweight. Women get overweight because they have PCOS, not the other way around,” Silber added.

“PCOS is all related to overabundance of follicles, which derange the beautiful, regular clockwork of ovarian stimulation that leads to regular 28-day ovulatory cycles,” Silber added. “If you take one ovary out of a young woman with PCOS, her cycles will become regular, and she will start ovulating. If a woman with PCOS goes into her late 40s or 50s, all of a sudden, her ovulation will become regular because she has been losing 1,000 eggs a day for years, as all women do, and when she gets to a reasonable number of eggs, the PCOS goes away.”

Shifting the focus away from the scale and toward the biological processes that define PCOS itself is key to improving care and research going forward.

The problem with a one-size-fits-all approach in PCOS

Many patients with PCOS are effectively invisible to the dominant care model because they don’t match the “overweight with PCOS” stereotype. Lean women who meet diagnostic criteria but have normal or low BMI often go underrecognized or misdiagnosed. Their needs are often overlooked because clinicians and researchers have long assumed that weight must be a central factor.

The problem begins in how we define PCOS. “One of the issues with the current research is treating PCOS as a one-size-fits-all diagnosis. The current Rotterdam criteria used today actually consists of four different phenotypes of PCOS, with limited evidence suggesting these phenotypes may have different trajectories and associated risks. Yet most women and clinicians are not aware of this,” said Copp.

“The expanded Rotterdam diagnostic criteria include women with milder symptoms, including those without insulin resistance, with a healthy BMI. Weight loss is not appropriate for these women,” said Copp.

PCOS symptoms can also overlap with symptoms of hypothalamic amenorrhea, which is caused by over-exercising and disordered eating. “Mislabelling these women with PCOS prevents them from receiving care for their actual issue, which can have serious consequences (e.g., exacerbated disordered eating, bone loss),” Copp warned.

Since research and care often collapse all phenotypes into one group, metabolic risks get assumed rather than examined. Women without insulin resistance or androgen excess may be pushed toward needless or harmful weight-centric interventions.

The harms go beyond missed treatment. Women with PCOS face elevated rates of mental health conditions: the odds of depression and anxiety are over 2.5× higher compared to women without PCOS. Self-report studies suggest 52% of women with PCOS show depression-like symptoms, and 26% show anxiety-like symptoms. These mental health burdens may worsen under a care model that labels symptom persistence as patient failure to lose weight.

“PCOS is totally misunderstood by most of the fertility world. There are lots of research papers written about it every year, and that has created a mess of mixed-up messages, chaos and confusion. The truth is, most of that research is no longer necessary because there is a clear explanation for what causes PCOS. It’s caused by having an inordinately large number of eggs,” said Silber.

Emerging alternatives to the weight-loss paradigm

Instead of focusing on weight loss as the main target, clinicians and researchers are starting to turn toward approaches that target underlying biology – hormone signalling, insulin sensitivity, lifestyle quality and mental health.

Medications such as metformin and supplements like myo‑inositol are part of that shift. For example, studies show myo-inositol improves insulin sensitivity and reduces androgen levels in women with PCOS. Metformin is also commonly prescribed to improve insulin sensitivity in women with PCOS.

However, not all researchers and clinicians agree this should be a primary treatment avenue. “PCOS is not an early version of diabetes, so we shouldn’t be putting these women on metformin. PCOS is not caused by insulin resistance,” said Silber. 

“Curing obesity can help women stay healthy and can prevent many diseases, but PCOS isn’t one of them,” Silber added.

Hormonal treatments are growing in popularity as an alternative to the weight loss paradigm. “We know what causes PCOS, and we know how to treat it,” said Silber. “Women who want to become pregnant should use mini-IVF. Women with PCOS who don’t want to get pregnant should be on hormonal contraception until they are in their 40s.”

Lifestyle interventions remain important, but the focus is shifting. Instead of prescribing weight loss diets, the emphasis now is on movement for strength and function, nutrition for hormone and metabolic support rather than calorie restriction and stress or sleep management as core elements.

Another approach gaining traction is the Health at Every Size (HAES) framework and intuitive-eating methods, which prioritise body respect, symptom management and metabolic health rather than targeting BMI. This weight-neutral stance can reduce the psychological burden of “you must lose weight” messages.

Where the guidelines are (and aren’t) evolving

The 2023 International Evidence-Based Guideline for PCOS describes one of the clearest shifts toward individualized care. Instead of prescribing one-size-fits-all interventions, it stresses that patient values, preferences and phenotypes should guide decision making. The guideline expands its scope beyond reproduction and metabolism to include psychological, cardiovascular and sleep assessments. It also highlights the need to reduce weight stigma and promote emotional well-being.

However, although mental health gets more visibility in the new guidance, psychological care is not embedded deeply across all recommendations. Also, HAES or truly weight-neutral strategies are not mentioned explicitly, limiting how far new paradigms can go within current standards.

In multidisciplinary centres, endocrinologists, dietitians and psychologists are collaborating to create care plans tailored to phenotype and symptom burden rather than BMI alone. In such practices, a patient might receive psychological support before any weight-based intervention or be offered fertility or hormone therapies without default weight loss mandates.

As guidelines evolve, there also needs to be parallel shifts in research, funding, training and care models.