Polycystic Ovary SyndromeNCT06204965
Time-Restricted Eating as a Dietary Intervention for Polyendocrine Metabolic Ovarian Syndrome (PMOS): Protocol for a Randomized Controlled Trial
A study testing Time-restricted eating in people with Polycystic Ovary Syndrome, run by Joanna Bajerska at 1 site in Poland.
Trial summary
Polyendocrine Metabolic Ovarian Syndrome (PMOS), previously known as PCOS, is a common endocrine disorder associated with metabolic, reproductive, and hormonal abnormalities. Growing evidence suggests that time-restricted eating (TRE) may improve body weight regulation, insulin sensitivity, hormonal balance, and… Read more about this study
- Who is it for?
- Ages 18 to 40 years, women only
- Conditions the study is for
- Polycystic Ovary Syndrome
- What is being tested?
- Time-restricted eating
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 84 participants
- Where
- 1 sitePoland
- Study dates
- 9 Jan 2027to 31 Mar 2028
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- Women only
- No healthy volunteers
- Adult
Eligible participants will be women aged 18-40 years with a BMI of 25-40 kg/m² and a physician-established diagnosis of PMOS established according to the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome . The exclusion criteria, assessed at the screening visit by structured interview and review of medical documentation, will be:
- use within the previous 3 months of medications or supplements affecting carbohydrate or lipid metabolism, body weight, reproductive hormones including hormonal contraceptives, antiandrogens, glucocorticoids, weight-loss medications, insulin-sensitizing agents (e.g., metformin, inositols), probiotic or prebiotic supplements;
- antibiotic treatment within the previous 3 months
- smoking within the previous 3 months or alcohol consumption >100 g/week;
- participation in competitive sports or structured athletic training;
- significant body weight fluctuations (>5%) during the 3 months preceding study enrollment;
- current or past diagnosis of anorexia nervosa, bulimia nervosa, binge eating disorder, or other clinically significant eating disorders;
- pregnancy or breastfeeding;
- shift work or night work;
- diagnosed type 1 or type 2 diabetes.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Poland1 site
Poznań University of Life Sciences
Poznan, Greater Poland Voivodeship, 60-637
Joanna Bajerska, Assoc. Prof., 8466056 ext. + 48 61, Joanna.bajerska@up.poznan.pl
Joanna M Pieczyńska-Zając, M.Sc., 660950786 ext. +48, joanna.pieczynska@up.poznan.pl
About this study
Polyendocrine Metabolic Ovarian Syndrome (PMOS), previously known as PCOS, is a common endocrine disorder associated with metabolic, reproductive, and hormonal abnormalities. Growing evidence suggests that time-restricted eating (TRE) may improve body weight regulation, insulin sensitivity, hormonal balance, and menstrual function in women with PMOS. However, the mechanisms underlying these benefits remain unclear, particularly regarding the role of the gut microbiota and neurohormonal pathways.
This randomized controlled trial will investigate whether combining an 8-hour TRE regimen with Healthy Eating Plate dietary recommendations provides greater benefits than dietary recommendations alone. Women aged 18-40 years with PMOS and overweight or obesity will participate in an 8-week intervention. The study will assess changes in gut microbiota composition, microbial metabolites, metabolic health, hormonal profile, neurohormonal markers, and body composition.
The study is expected to provide novel insights into the interactions between meal timing, gut microbiota, neuroendocrine regulation, and clinical manifestations of PMOS, contributing to the development of more effective and sustainable dietary strategies for this condition.
Read the detailed description
Polyendocrine Metabolic Ovarian Syndrome (PMOS), formerly referred to as Polycystic Ovary Syndrome (PCOS), affects a substantial proportion of women of reproductive age and is characterized by reproductive, endocrine, and metabolic disturbances. In addition to hormonal dysregulation involving the hypothalamic-pituitary-ovarian axis, women with PMOS frequently experience obesity, insulin resistance, hyperinsulinemia, menstrual irregularities, and impaired fertility. Recent research indicates that the gut microbiota and the gut-brain axis may play important roles in the development and progression of the syndrome. Gut-derived metabolites, including short-chain fatty acids, lipopolysaccharides, and neuroactive compounds such as GABA, may influence both metabolic and reproductive functions.
Time-restricted eating (TRE), an eating pattern that limits food intake to a specific daily time window without necessarily restricting calories, has emerged as a promising intervention for individuals with metabolic disorders. Previous studies suggest that TRE may improve insulin sensitivity, glucose metabolism, lipid profile, body weight, and reproductive outcomes in women with PMOS. Furthermore, evidence from both human and animal studies indicates that TRE may beneficially alter the composition and diversity of the gut microbiota. Despite these findings, the biological mechanisms linking meal timing, gut microbiota changes, neurohormonal regulation, and clinical improvements in PMOS remain insufficiently understood.
To address this knowledge gap, this study has been designed as a two-arm randomized controlled trial involving women aged 18 to 40 years with PMOS and a BMI between 25 and 40 kg/m². Participants will be randomly assigned to either a control group following Healthy Eating Plate recommendations without meal-timing restrictions or an intervention group following the same dietary recommendations combined with a 16:8 TRE regimen, restricting food intake to an 8-hour daily eating window. The intervention will last eight weeks.
The primary objective is to determine whether TRE can induce favorable changes in intestinal microbiota composition and microbial metabolites. Secondary outcomes include changes in glucose and lipid metabolism, insulin resistance, hormonal profile, neurohormonal markers such as kisspeptin and GABA, anthropometric measurements, body composition, and energy intake. Comprehensive assessments will include blood analyses, stool microbiota sequencing, metabolic and hormonal measurements, dietary intake evaluation, and physical activity assessment.
A major strength of the study is its ability to isolate the effect of meal timing because both groups receive identical dietary quality recommendations. This design allows researchers to evaluate whether the timing of food consumption independently contributes to improvements in PMOS-related outcomes. By integrating microbiological, metabolic, and neuroendocrine assessments, the trial is expected to provide a comprehensive understanding of the gut microbiota-brain-reproductive axis in PMOS.
The researchers anticipate that this will be one of the largest studies examining TRE in women with PMOS. The findings may help clarify the mechanisms through which TRE influences metabolic and reproductive health and support the development of evidence-based, practical, and sustainable dietary recommendations for women affected by this condition.
- Conditions
- Polycystic Ovary Syndrome
- Being tested
- Time-restricted eating
- Keywords
- Intermittent Fasting, Microbiota, Neurotransmitter Agents, Polycystic Ovary Syndrome, Polyendocrine Metabolic Ovarian Syndrome
- Medical subject headings
- Polycystic Ovary Syndrome, Intermittent Fasting
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Time-restricted eatingBehavioural
Time-restricted eating (TRE) is a dietary pattern where food intake is restricted to 8 hours of the day with no limitation on nutrient quality or quantity. Participants assigned to the intervention group will eat their usual diet from 9:00 a.m. to 5:00 p.m., and then fast until the next day (protocol 8/16). During the 16-hour fast, only hot and cold drinks will be allowed, i.e. coffee, tea or tea and water, but all products and dishes with energy value (including coffee cream, sweet teas, alcohol, snacks, etc.) will be prohibited. The TRE protocol will be implemented 7 days a week for a period of 2 months (8 weeks).
| Study group | Role | What they receive |
|---|---|---|
| Time-restricted eating group (TRE group) | Experimental | Participants in the TRE group will be instructed to consume all foods and energy-containing beverages between 9:00 a.m. and 5:00 p.m. (8-hour eating window) and fast for the remaining 16 hours until the following day (a 16:8 protocol). Participants randomized to the intervention group will receive the same dietary recommendations but will additionally be instructed to follow a time-restricted eating (TRE) regimen. Receives: Behavioral: Time-restricted eating |
| Non-fasting group | No intervention | Participants assigned to the control group will receive dietary advice based on the Healthy Eating Plate model and will be instructed to consume their diet ad libitum, without prescribed energy restriction. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in glucose metabolism - Homeostatic Model Assessment of Insulin Resistance
Insulin resistance will be evaluated using the Homeostasis ModelAssessment Method. The HOMA-IR (Homeostatic Model Assessment of Insulin Resistance) will be calculated using the following formula: HOMA - IR = fasting glucose [mmol/L] × fasting insulin [μIU/mL]/22.5
Measured: Week 0 (pre-intervention) - week 8 (post-intervention)
Secondary outcomes (10)
Change in energy consumption
Dietary intake will be assessed using a validated 72-item Semi-Quantitative Food Frequency Questionnaire (72-item SQ-FFQ) available on the DietTools4U platform and a 3-day dietary record (two weekdays and one weekend day). The use of these complementary methods will enable both the assessment of habitual dietary patterns and the detailed evaluation of recent food intake.
Measured: Week 0 (pre-intervention) - week 8 (post-intervention)
Change in body composition
Body composition will be measured using dual-energy X-ray absorptiometry (DXA) as a method that uses the phenomenon of weakening the beam of ionizing radiation passing through tissues of various densities. This method is safe and non-invasive. The mass of adipose tissue, including visceral fat tissue, the mass of lean tissue are measured (expressed in the same unit - kilograms)
Measured: Week 0 (pre-intervention), week 4, week 8 (post-intervention)
Change in glucose metabolism - glucose concentration
Blood will be collected four times from the antecubital vein on an empty stomach, into test tubes with clotting granules (a single sample will amount to a total of 18 ml). The serum will be obtained by centrifugation of a venous blood clot. The glucose will be determined using standard enzymatic colorimetric methods on an automated biochemical analyzer in a certified external diagnostic laboratory (expressed in the unit - mmol/L).
Measured: Week 0 (pre-intervention) - week 8 (post-intervention)
Change in glucose metabolism - insulin concentration
Blood will be collected four times from the antecubital vein on an empty stomach, into test tubes with clotting granules (a single sample will amount to a total of 18 ml). The serum will be obtained by centrifugation of a venous blood clot. The insulin concentration will be performed using the ELISA enzyme-linked immunosorbent assay (expressed in the unit - μIU/mL).
Measured: Week 0 (pre-intervention) - week 8 (post-intervention)
Change in lipid profile
Blood will be collected four times from the antecubital vein on an empty stomach, into test tubes with clotting granules (a single sample will amount to a total of 18 ml). The serum will be obtained by centrifugation of a venous blood clot. Total cholesterol (T-C), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and triglycerides concentrations will be using standard enzymatic colorimetric methods on an automated biochemical analyzer in a certified external diagnostic laboratory. The nonHDL-C parameter will be calculated using the formula: nonHDL-C = T-C - HDL-C (expressed in the same unit - mg/dl or mmol/l).
Measured: Week 0 (pre-intervention) - week 8 (post-intervention)
Change in selected hormonal parameters
Blood will be collected four times from the antecubital vein on an empty stomach, into test tubes with clotting granules (a single sample will amount to a total of 18 ml). The serum will be obtained by centrifugation of a venous blood clot. Hormonal parameters (FSH, LH, testosterone, SHBG), will be performed using the ELISA enzyme-linked immunosorbent assay (expressed in the same unit - pg/ml)
Measured: Week 0 (pre-intervention) - week 8 (post-intervention)
Change in circumferences
Waist and hip measurements will be taken using an elastic tape. Waist circumference measurement - the tape is placed horizontally or slightly obliquely halfway between the lower edge of the ribs and the upper crest of the ilium. Measurement performed during apnea.
Measured: Week 0 (pre-intervention), week 4, week 8 (post-intervention)
Change in body weight
Body weight measurement in a standing position, without shoes, in light clothing, on an electronic scale with an accuracy of 0.1 kg.
Measured: Week 0 (pre-intervention), week 4, week 8 (post-intervention)
Change in bone density
Bone density will be measured using dual-energy X-ray absorptiometry (DXA) as a method that uses the phenomenon of weakening the beam of ionizing radiation passing through tissues of various densities. This method is safe and non-invasive.
Measured: Week 0 (pre-intervention), week 4, week 8 (post-intervention)
Change in circulating GABA and kisspeptin concentrations
Blood will be collected four times from the antecubital vein on an empty stomach, into test tubes with clotting granules (a single sample will amount to a total of 18 ml). The serum will be obtained by centrifugation of a venous blood clot. Kisspeptin and gamma-aminobutyric acid concentrations will be performed using the ELISA enzyme-linked immunosorbent assay.
Measured: Week 0 (pre-intervention) - week 8 (post-intervention)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Jan 2024
- Study start9 Jan 2027 (estimated)
- Primary completion31 Dec 2027 (estimated)
- Study completion31 Mar 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Polycystic Ovary SyndromeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Women with Polycystic Ovary Syndrome (n=84), aged 18-40.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 84 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Joanna Bajerska
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Joanna Bajerska, Poznan University of Life Sciences
- Investigators
- Agata Chmurzyńska, Prof., Study chair, Department of Human Nutrition and Dietetics, Poznań University of Life Sciences
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06204965
- Sponsor's protocol ID
- 646/23
- Status last verified
- Sep 2026
- First submitted
- 3 Jan 2024
- Last updated
- 16 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Numerical data, statistics and graphs data will be deposited in the Open Data Repository RepOD - the PULS institutional repository, and made publicly available in the Repository at the latest at the time when the publication presenting research data is published including a maximum 36-month embargo period due to the requirements and specifics of the publication of the article presenting the research results. Upon publication, the embargo will be lifted immediately. Unless there is a clear indication to the contrary, the data will be made available in the RepOD repository under a CC BY 4.0 license. Data not stored in RepOD will be stored long term as described in 3.1. Raw and processed data will be stored for at least 10 years. Personal data will be deleted after the pseudonymization process.
Publications
Li C, Xing C, Zhang J, Zhao H, Shi W, He B. Eight-hour time-restricted feeding improves endocrine and metabolic profiles in women with anovulatory polycystic ovary syndrome. J Transl Med. 2021 Apr 13;19(1):148. doi: 10.1186/s12967-021-02817-2.
PubMed 33849562Torres PJ, Ho BS, Arroyo P, Sau L, Chen A, Kelley ST, Thackray VG. Exposure to a Healthy Gut Microbiome Protects Against Reproductive and Metabolic Dysregulation in a PCOS Mouse Model. Endocrinology. 2019 May 1;160(5):1193-1204. doi: 10.1210/en.2019-00050.
PubMed 30924862Liao B, Qiao J, Pang Y. Central Regulation of PCOS: Abnormal Neuronal-Reproductive-Metabolic Circuits in PCOS Pathophysiology. Front Endocrinol (Lausanne). 2021 May 28;12:667422. doi: 10.3389/fendo.2021.667422. eCollection 2021.
PubMed 34122341Tremellen K, Pearce K. Dysbiosis of Gut Microbiota (DOGMA)--a novel theory for the development of Polycystic Ovarian Syndrome. Med Hypotheses. 2012 Jul;79(1):104-12. doi: 10.1016/j.mehy.2012.04.016. Epub 2012 Apr 27.
PubMed 22543078Minabe S, Iwata K, Tsuchida H, Tsukamura H, Ozawa H. Effect of diet-induced obesity on kisspeptin-neurokinin B-dynorphin A neurons in the arcuate nucleus and luteinizing hormone secretion in sex hormone-primed male and female rats. Peptides. 2021 Aug;142:170546. doi: 10.1016/j.peptides.2021.170546. Epub 2021 Mar 29.
PubMed 33794282