Treatment for women with endometriosis is only partially or temporarily effective. Moreover, medical hormonal treatment is associated with debilitating side effects and interferes with fertility, while surgery has a relatively high risk of complications. Meanwhile, women with endometriosis show increasing interest in implementing lifestyle interventions to alleviate symptoms and improve health-related quality of life (HRQoL). Integrating these lifestyle interventions can provide a holistic approach to the treatment of this debilitating disease. However, scientific evidence supporting the effectiveness of these interventions is limited. This study is designed to investigate the effectiveness of two lifestyle interventions and the combination of both: an anti-inflammatory diet intervention (AIDI) could improve immune cell function and reduce inflammation, resulting in improved HRQoL and alleviating pain. In addition, the integration of cognitive behavioural therapy (CBT) aims to provide insight into pain mechanisms and coping with pain, and to assist in sustaining dietary adjustments.

The Pain in Endometriosis And the Relation to Lifestyle (PEARL) study is a five-arm randomised controlled trial with a pre-post factorial design with two factors: an AIDI and CBT. The study population will consist of 250 premenopausal women, of whom 200 are diagnosed with endometriosis and experience pain symptoms and 50 are healthy controls (HC). Women with endometriosis will be recruited from one academic tertiary and five secondary hospitals in the Netherlands. They will be randomised (1:1:1:1) among four intervention groups: standard care (SC) (SC group), SC and an AIDI (SC + AIDI group), SC and CBT (SC + CBT group), and SC, AIDI and CBT (SC + AIDI + CBT group). Women with endometriosis will visit the hospital twice during the intervention period, at the start (T0) and end (T2) of the 13-week intervention period. HC will not undergo any of the interventions and will have one hospital visit (T0). Participants will complete questionnaires regarding pain symptoms, HRQoL, physical activity level, sleep, diet quality, pain cognitions, and stress at T0 and T2. Furthermore, they are instructed to collect menstrual effluent, a vaginal swab and a faecal sample. During the study visits, peripheral blood will be drawn and scalp hair samples will be taken. The primary outcome is average pain, measured using a numerical rating scale. Secondary outcomes focus on HRQoL, inflammation, immune system characteristics, vaginal- and gut microbiome, and hair cortisol levels. These are considered to reflect potentially underlying mechanisms of the effect of both interventions on the primary outcome. Biological samples and questionnaires of women with endometriosis and HC will be compared to establish the differences in secondary outcomes.

This study protocol has been approved (approval number: NL86247.091.24) by the METC Oost-Nederland from Radboud University Medical Centre on July 11, 2024. Prior to participation, participants are required to provide informed consent. The results will be widely disseminated through scientific peer-reviewed journals, and presentation to a broad audience in scientific meetings, congresses, patient meetings, as well as in policy-relevant forums.

NCT06332560.

Metabolic bariatric surgery (MBS) can lead to substantial fat-free mass loss (FFML) due to malnutrition, decreased protein intake and insufficient physical activity. Disproportional FFML has been associated with an increased risk for adverse health outcomes. Resistance training (RT) combined with protein intake contributes to maintenance and increase of fat-free mass (FFM) in healthy individuals. However, it is unclear whether RT and protein supplementation can prevent FFML after MBS.

In the EffectiveNess of pRotein supplementatIon Combined witH resistance Exercise training to counteract Disproportional fat-free mass loss following metabolic bariatric surgery (ENRICHED) randomised controlled trial, 400 patients scheduled to undergo MBS will be randomised in a 1:1 ratio to the ENRICHED perioperative care programme (intervention group) or the standard perioperative care programme of the Dutch Obesity Clinic (control group). The study is currently recruiting participants at two centres in the Netherlands: Nieuwegein and Amsterdam. The postoperative standard programme consists of 13 group sessions spread over a period of 18 months. As part of the ENRICHED programme, RT and protein supplementation will be added 3 weeks after MBS. Additional whole-body RT consists of home-based training sessions two to three times a week, and supervised RT sessions of 45–60 min once weekly, performed at 60–75% of one-repetition maximum (1-RM). Protein supplementation will start by adding 20 g of whey protein to the daily intake. The supplementation will be gradually increased with 20 g every 4 weeks until a total of 60 g whey protein a day is reached. After 12 weeks of protein supplementation, the focus shifts towards incorporating protein-rich food products into the daily dietary intake. The primary endpoint is the prevalence of disproportional FFM loss, defined as FFML/total weight loss ≥30%, at 3 months post-MBS. Secondary endpoints are differences in body composition, muscle strength and function, cardiorespiratory fitness, (cardio)metabolic health, health-related quality of life, gastrointestinal discomfort, cost-effectiveness of the intervention and treatment satisfaction. Outcomes will be assessed preoperatively and at 3, 6 and 12 months postoperatively.

The study protocol V.2.0 was approved by the Medical Research Ethics Committee Oost-Nederland (NL-OMON57119) on 9 April 2025. All participants will provide written informed consent prior to enrolment. Study findings will be disseminated through peer-reviewed publications and conference presentations. Insights gained in this study will provide evidence for a patient-tailored intervention that could be implemented in clinical practice.

NCT07156552.