Precision Nutrition For PCOS/PMOS: Translating Dietary Patterns, Metabolic Phenotypes, And Nutraceutical Evidence Into Practical Care

Polycystic ovary syndrome (PCOS), renamed polyendocrine metabolic ovarian syndrome (PMOS) through a 2026 global consensus process, is a heterogeneous endocrine-metabolic condition in which insulin resistance, hyperandrogenism, adipose dysfunction, reproductive disturbance, and psychological burden interact across the life course. Nutrition is first-line care, yet a single "PCOS diet" is not supported by current evidence. This narrative review synthesizes recent guidelines, systematic reviews, meta-analyses, and selected randomized trials to develop a practical precision-nutrition framework for PCOS/PMOS. Evidence supports sustainable healthy eating patterns rather than one universal macronutrient prescription. Energy restriction is useful when clinically indicated; dietary quality remains important independent of weight change. DASH, Mediterranean-style, low-glycemic-index/load, and other minimally processed, fiber-rich patterns improve selected anthropometric and metabolic outcomes, while certainty for reproductive endpoints is lower. Lower-carbohydrate and ketogenic strategies may produce short-term benefits but require attention to nutritional adequacy, adherence, lipid response, fertility plans, and eating-disorder risk. Inositol, vitamin D, omega-³ fatty acids, and probiotics may be considered as adjuncts for selected patients, but heterogeneity in products, doses, and study quality prevents routine universal supplementation. A phenotype-informed approach should integrate glycemic status, body composition, lipid and liver risk, reproductive goals, medications, culture, food access, sleep, mental health, and patient preference. The review proposes an assessment algorithm, evidence-to-practice tables, and a food-first plate model. Nutrition should be framed as supportive, individualized chronic-disease care, not a cure, moral test, or replacement for medical treatment.