Abstract / Summary
Context: Polyendocrine metabolic ovarian syndrome (PMOS; previously polycystic ovarian syndrome i.e., PCOS) is common in reproductive-age women, who often have higher BMI classification. This is assumed to stem from lower resting energy expenditure (REE), influencing lifestyle intervention guidelines. However, evidence for reduced REE in women with PMOS compared with those without is inconsistent. Objective: To systematically search and meta-analyse the existing literature to estimate and describe the difference in REE between women with and without PMOS. Data Sources: PubMed, MEDLINE/EBSCO, and Web of Science were searched for published research from January 1990 through May 2025, and the searches were updated through September 2026. The update identified no additional eligible studies. Study Selection: Studies that measured REE in women living with PMOS, both with and without control arms of women without PMOS, were included. Data Extraction: Bibliometric, demographic, and REE data were extracted by one investigator and checked in triplicate. Data Synthesis: Thirteen studies were included in a Bayesian arm-based multiple condition comparison (i.e., network) type meta-analysis model with informative priors to compare both mean REE, and between-person variation in REE, between women with and without PMOS. Mean REE differed between groups by 31 kcal/day [95% quantile interval: -44 to 113 kcal/day] and the contrast ratio for between-person standard deviations was 0.98 [95% quantile interval: 0.71 to 1.32]. Conclusions: These findings indicate that REE does not meaningfully differ between women with and without PMOS. Group-level differences in resting energy expenditure are small, insignificant, or not physiologically relevant.