By Ro Huntriss, Consultant Dietitian and Founder of Fertility Dietitian UK
Polycystic ovary syndrome (PCOS), now known as Polyendocrine Metabolic Ovarian Syndrome (PMOS), is increasingly recognised as a complex condition extending far beyond reproductive health. But what does this evolving understanding mean for nutrition care? In this blog, Ro Huntriss, Consultant Dietitian and Founder of Fertility Dietitian UK, explores the latest evidence surrounding PMOS, including its different clinical presentations, the role of dietary interventions and why personalised nutrition approaches are essential for effective management. Discover how healthcare professionals can translate emerging research into practical, individualised care, and read to the end for an exclusive 10% discount on The PMOS (PCOS) Nutrition Course, available until 6 December 2026.
The name has changed because our understanding has changed. But what does this mean for nutrition care, and what should healthcare professionals be doing differently?
Polyendocrine Metabolic Ovarian Syndrome (PMOS), formerly known as polycystic ovary syndrome (PCOS), is a complex endocrine condition affecting reproductive, metabolic and psychological health.
For many years, clinical discussions have focused predominantly on irregular periods, cysts (follicles) on the ovaries, fertility difficulties, excess hair growth and weight management. However, research increasingly highlights the broader, multisystem nature of the condition and the considerable variation in how individuals experience it.
For healthcare professionals, particularly those providing nutrition and lifestyle support, this has important implications.
If PMOS does not present in the same way in every individual, nutrition care cannot follow a single prescription.
From PCOS to PMOS: what has actually changed?
In May 2026, an international consensus proposed the name Polyendocrine Metabolic Ovarian Syndrome (PMOS) to replace PCOS, better reflecting the condition’s complex endocrine and metabolic characteristics.1
The proposed terminology acknowledges something researchers and clinicians have increasingly recognised: the condition extends well beyond the ovaries.
The 2023 International Evidence-Based Guideline for PCOS remains a key foundation for clinical management, while emerging research continues to develop our understanding of the underlying biology.2
At its core, PMOS involves interacting reproductive, androgenic and metabolic processes, although the relative contribution of each varies considerably between individuals.
This complexity helps explain why two people with the same diagnosis may experience very different symptoms, health risks and responses to treatment.
PMOS is more than a reproductive condition
PMOS is characterised by considerable clinical heterogeneity. Understanding the different physiological processes involved is essential for effective nutrition care.3,4
Hyperandrogenism
Hyperandrogenism is a central feature of many PMOS presentations and may be identified through elevated circulating androgen concentrations, clinical symptoms or both.
Common manifestations include hirsutism, acne and androgen-dependent hair loss.
However, androgen excess is not simply responsible for visible symptoms. Androgens also interact with ovarian function, adipose tissue and metabolic pathways, contributing to the broader pathophysiology of PMOS.
Importantly, clinical symptoms do not always correlate directly with circulating androgen concentrations, and hyperandrogenism is not present in every diagnostic phenotype.
Ovulatory dysfunction
Ovulatory dysfunction may manifest through irregular or infrequent menstrual cycles, anovulation and difficulties conceiving.
Although PMOS is a common cause of anovulatory infertility, a diagnosis does not necessarily mean someone will experience infertility. Some individuals ovulate spontaneously, and reproductive outcomes vary.
For healthcare professionals, understanding whether menstrual regularity, fertility or another aspect of reproductive health is a patient’s primary concern can help guide management priorities.
Insulin resistance and metabolic dysfunction
Insulin resistance is a common feature of PMOS and plays an important role in its metabolic and reproductive manifestations.
Reduced insulin sensitivity can lead to compensatory hyperinsulinaemia, which may contribute to increased ovarian androgen production and altered metabolic regulation.
Crucially, insulin resistance can occur independently of BMI, including in individuals who are not living with overweight or obesity – commonly termed lean PMOS.
PMOS is also associated with an increased risk of impaired glucose regulation, type 2 diabetes, dyslipidaemia, hypertension and other cardiometabolic risk factors. Emerging research has also highlighted associations with metabolic dysfunction-associated steatotic liver disease (MASLD).
This makes metabolic assessment relevant across the spectrum of body weights.
Beyond hormones and metabolism
The implications of PMOS extend further still.
Individuals may experience increased risks of obstructive sleep apnoea, anxiety, depression, reduced quality of life and disordered eating. PMOS is also associated with increased risks of pregnancy complications, including gestational diabetes and hypertensive disorders of pregnancy.
Not everyone experiences these complications, but recognising the broader clinical picture supports more comprehensive, person-centred care.
One condition, many presentations: why phenotype matters
One of the challenges in PMOS management is that two individuals meeting the same diagnostic criteria may have very different clinical priorities.
Four commonly described adult phenotypes illustrate this heterogeneity5
- A – Classic – Hyperandrogenism, ovulatory dysfunction and polycystic ovarian morphology
- B Classic – Hyperandrogenism and ovulatory dysfunction, without polycystic ovarian morphology
- C Ovulatory – Hyperandrogenism and polycystic ovarian morphology, with preserved ovulation
- D – non–hyperandrogenic – Ovulatory dysfunction and polycystic ovarian morphology, without hyperandrogenism
These phenotypes help describe differences in presentation, although they do not reliably predict an individual’s metabolic risk or response to a particular dietary intervention.
For example, one patient may present with insulin resistance and metabolic risk factors, while another may primarily seek support for irregular menstrual cycles or fertility. A third may have significant concerns about body image or eating behaviours.
Their nutrition priorities are unlikely to be identical.
The key is not simply identifying a phenotype, but understanding the individual behind the diagnosis.
Is there a specific PMOS diet?
Despite the growing number of dietary interventions being investigated, there is currently no single diet established as superior for everyone with PMOS.
The 2023 international guideline concludes that evidence does not support one dietary composition over another for improving anthropometric, metabolic, hormonal, reproductive or psychological outcomes.
Instead, it recommends sustainable healthy eating approaches tailored to individual preferences, goals and circumstances.
Research has explored several approaches, including:
- Mediterranean-style diets: Rich in vegetables, fruit, whole grains, legumes, nuts and unsaturated fats, with potential benefits for cardiometabolic health.6
- Lower-glycaemic-index diets: May support glycaemic regulation and some metabolic outcomes, although findings vary between studies.7
- Carbohydrate quality and quantity: Both may influence glycaemic responses, but carbohydrate restriction is not universally necessary.8
- Higher-protein approaches: May support satiety and weight management in some individuals, although evidence for superiority over other balanced diets remains limited.9
- Energy-restricted diets: Can support weight management and metabolic improvements when clinically appropriate, but should not be routinely prescribed to everyone.10
- Time-restricted eating: Emerging studies suggest potential metabolic benefits, although longer-term evidence remains limited.11
- Ketogenic diets: Some short-term studies report improvements in weight and metabolic markers, but sustainability, nutritional adequacy and long-term outcomes require further investigation.12
Dietary interventions have demonstrated benefits for weight management, insulin sensitivity, reproductive hormones and menstrual regularity. However, growing evidence does not point to a single optimal PMOS diet13, but rather highlights the need for healthcare professionals to critically evaluate the evidence and tailor nutritional strategies to individual needs.
What should personalised PMOS nutrition care look like?
Personalised PMOS nutrition care requires more than selecting a dietary pattern. Healthcare professionals must consider the interaction between metabolic, reproductive and psychological health, alongside individual priorities and the evolving evidence base.
While there is no single approach suitable for everyone, several principles can guide clinical decision-making.
1. Understand the person’s clinical priorities
Establish what matters most to the individual.
Their goals may include improving metabolic health, managing symptoms, supporting fertility, achieving sustainable weight management or developing a healthier relationship with food. These priorities should guide the direction of care.
2. Assess the whole clinical picture
Weight and BMI alone cannot adequately describe metabolic health or nutritional needs.
Assessment should consider relevant clinical history, biochemical markers, menstrual and reproductive health, dietary intake, physical activity, sleep, psychological wellbeing and eating behaviours.
The international guideline recommends assessment of glycaemic status at diagnosis, with an oral glucose tolerance test identified as the most accurate approach, regardless of BMI.
3. Identify modifiable priorities
Nutritional strategies should address the individual’s needs and risk factors.
For some, this may involve improving dietary fibre intake, carbohydrate quality or overall dietary patterns. For others, adequate energy intake, meal regularity or reducing restrictive eating behaviours may be more appropriate.
The aim is to select interventions with a sound evidence base that are achievable within the person’s circumstances.
4. Agree realistic, sustainable goals
The guideline recommends healthy lifestyle behaviours for everyone with PMOS, regardless of body weight.
Physical activity, nutrition, sleep and behavioural support can contribute to health improvements even without weight loss.
For individuals seeking weight management, an individualised approach that considers preferences, previous experiences and potential risks of weight stigma or disordered eating is essential.
5. Review and adapt
PMOS management is rarely static.
Symptoms, metabolic risk, reproductive goals and life circumstances can change over time. Nutrition interventions should therefore be reviewed and adapted according to clinical outcomes, patient preferences and emerging evidence.
Translating the evidence into practice: The PMOS Nutrition Course
Early in my career working as a weight management dietitian, I recognised that many women with PMOS needed more individualised support than conventional weight management advice could offer.
Their challenges extended beyond body weight, and standard approaches did not always adequately address their metabolic, hormonal, reproductive or psychological needs.
With research into dietary patterns, nutritional supplements, metabolic health and reproductive outcomes continuing to develop, staying up to date is only part of the challenge. Healthcare professionals also need to critically evaluate emerging evidence and understand how to apply it across different clinical presentations.
This is why I created The PMOS (PCOS) Nutrition Course: to bring together the latest research, clinical guidance and practical application in one comprehensive professional training programme.
Designed for dietitians, nutritionists, doctors, nurses and other healthcare professionals working with PMOS patients, the course explores:
- The underlying pathophysiology, phenotypes and clinical presentations of PMOS.
- The evidence for different dietary patterns and how to individualise nutrition recommendations.
- Nutritional supplements, including inositols and emerging interventions.
- Weight management approaches and the role of pharmacological treatments.
- The developing evidence around the gut and reproductive microbiomes.
- Physical activity, sleep, stress and other lifestyle considerations.
The focus is not simply on understanding the science, but on applying it confidently in clinical practice.
PMOS nutrition care is evolving, and healthcare professionals have an important role in translating emerging research into effective, individualised support.
Ready to deepen your understanding of PMOS nutrition?
Explore The PMOS (PCOS) Nutrition Course to develop your knowledge of the latest evidence and gain the confidence to apply it in clinical practice. Use the code MYNUTRIWEB10 for 10% off (limited time only – valid until 6th December 2026).
References
- Teede HJ, Khomami MB, Morman R, Laven JSE, Joham AE, Costello MF, Patil M, Rees DA, Berry L, Cree MG, Zhao H, Norman RJ, Dokras A, Piltonen T; Global Name Change Consortium. Polyendocrine metabolic ovarian syndrome, the new name for polycystic ovary syndrome: a multistep global consensus process. Lancet. 2026 Jun 6;407(10545):2329-2339. doi: 10.1016/S0140-6736(26)00717-8. Epub 2026 May 12. PMID: 42119588.
- Teede HJ, Tay CT, Laven JJE, Dokras A, Moran LJ, Piltonen TT, Costello MF, Boivin J, Redman LM, Boyle JA, Norman RJ, Mousa A, Joham AE; International PCOS Network. Recommendations from the 2023 international evidence-based guideline for the assessment and management of polycystic ovary syndrome. Eur J Endocrinol. 2023 Aug 2;189(2):G43-G64. doi: 10.1093/ejendo/lvad096. PMID: 37580861.
- Armanini D, Boscaro M, Bordin L, Sabbadin C. Controversies in the Pathogenesis, Diagnosis and Treatment of PCOS: Focus on Insulin Resistance, Inflammation, and Hyperandrogenism. Int J Mol Sci. 2022 Apr 8;23(8):4110. doi: 10.3390/ijms23084110. PMID: 35456928; PMCID: PMC9030414.
- Dong J, Rees DA. Polycystic ovary syndrome: pathophysiology and therapeutic opportunities. BMJ Med. 2023 Oct 12;2(1):e000548. doi: 10.1136/bmjmed-2023-000548. PMID: 37859784; PMCID: PMC10583117.
- Azziz R, Kintziger K, Li R, Laven J, Morin-Papunen L, Merkin SS, Teede H, Yildiz BO. Recommendations for epidemiologic and phenotypic research in polycystic ovary syndrome: an androgen excess and PCOS society resource. Hum Reprod. 2019 Nov 1;34(11):2254-2265. doi: 10.1093/humrep/dez185. PMID: 31751476.
- Scannell N, Villani A, Moran L, Mantzioris E. The potential role of the Mediterranean diet for the treatment and management of polycystic ovary syndrome: a review of the pathophysiological mechanisms and clinical evidence. Proc Nutr Soc. 2025 May;84(2):176-187. doi: 10.1017/S0029665124007584. Epub 2024 Nov 19. PMID: 39558903.
- Saadati N, Haidari F, Barati M, Nikbakht R, Mirmomeni G, Rahim F. The effect of low glycemic index diet on the reproductive and clinical profile in women with polycystic ovarian syndrome: A systematic review and meta-analysis. Heliyon. 2021 Nov 9;7(11):e08338. doi: 10.1016/j.heliyon.2021.e08338. PMID: 34820542; PMCID: PMC8600081.
- Zhang X, Zheng Y, Guo Y, Lai Z. The Effect of Low Carbohydrate Diet on Polycystic Ovary Syndrome: A Meta-Analysis of Randomized Controlled Trials. Int J Endocrinol. 2019 Nov 26;2019:4386401. doi: 10.1155/2019/4386401. PMID: 31885557; PMCID: PMC6899277.
- Wang F, Dou P, Wei W, Liu PJ. Effects of high-protein diets on the cardiometabolic factors and reproductive hormones of women with polycystic ovary syndrome: a systematic review and meta-analysis. Nutr Diabetes. 2024 Feb 29;14(1):6. doi: 10.1038/s41387-024-00263-9. PMID: 38424054; PMCID: PMC10904368.
- Yang J, Liang J, Xu J, Lin T, Ye Q, Lin Q, Ji F, Shi D. The impact of dietary interventions on polycystic ovary syndrome patients with a BMI ≥25 kg/m2: A systematic review and meta-analysis of randomized controlled trials. Reprod Med Biol. 2024 Sep 30;23(1):e12607. doi: 10.1002/rmb2.12607. PMID: 39351128; PMCID: PMC11442045.
- Ranneh Y, Hamsho M, Shkorfu W, Terzi M, Fadel A. Effect of Intermittent Fasting on Anthropometric Measurements, Metabolic Profile, and Hormones in Women with Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis. Nutrients. 2025 Jul 25;17(15):2436. doi: 10.3390/nu17152436. PMID: 40806019; PMCID: PMC12348862.
- Diha AM, Uddin MSS, Anha KM, Bekele FD, Naima J, Al-Khulaifi AAS, Nassar AA, Huq MS. Effects of Ketogenic Diet (KD) on Metabolic, Endocrine, and Reproductive Outcomes in Overweight/Obese Women With Polycystic Ovary Syndrome (PCOS): A Systematic Review. Cureus. 2026 Feb 14;18(2):e103615. doi: 10.7759/cureus.103615. PMID: 41853422; PMCID: PMC12992147.
- Akbaş E, Samancı M, Öztürk YE. Nutrition interventions in women with polycystic ovary syndrome: a systematic review. Eur J Nutr. 2026 Jun 29;65(5):176. doi: 10.1007/s00394-026-04030-7. PMID: 42371137; PMCID: PMC13314694.
