Mediterranean Diet Education in Shift Nurses: Effects on Sleep, Activity, and Health Parameters

The Relationship Between Mediterranean Diet Education Given to Shift-Working Nurses and Sleep Quality, Physical Activity Level, Blood Parameters, and Anthropometric Measurements

This study aimed to evaluate the effects of Mediterranean diet education on sleep quality, physical activity levels, blood parameters, and anthropometric measurements among shift-working nurses.

Primary outcomes: Change in Mediterranean diet adherence and sleep quality scores from baseline to post-intervention.

Secondary outcomes: Changes in physical activity levels, anthropometric indices (e.g., BMI, waist-to-hip ratio), and blood parameters (fasting glucose, insulin, HOMA-IR, lipid profile).

Study Overview

• Status: Completed
• Conditions: Cardiovascular Diseases; Hypertension; Metabolic Syndrome; Type 2 Diabetes Mellitus (T2DM); Occupational Health; Obesity Prevention; Atheroscleroses
• Intervention / Treatment: Behavioral: Mediterranean Diet Education Program

Detailed Description

Background Shift work misaligns endogenous circadian rhythms with environmental light-dark cycles, predisposing workers to poor sleep, metabolic dysregulation, weight gain and cardiometabolic disease. Observational and experimental evidence indicates that dietary patterns rich in plant foods, monounsaturated fats and lean proteins-exemplified by the Mediterranean diet (MedDiet)-can attenuate inflammation, improve lipid and glycaemic profiles, and enhance subjective well-being. Educational interventions that reinforce MedDiet principles may therefore represent a pragmatic, low-risk strategy to mitigate health risks in shift-working nurses.

Study Desing Design: Single-group, pre-post intervention study Setting: Private general hospital in Muğla, Türkiye Sample Size: 130 nurses (≈80 % women) employed in rotating shifts, aged 18-55 y Allocation: Not applicable (no comparison arm)

Participant Eligibility Inclusion Criteria Registered nurse working ≥3 rotating shifts per month at the study hospital Age 18-55 years Written informed consent Exclusion Criteria Pregnancy or lactation Current participation in another lifestyle or drug trial Diagnosed sleep disorder requiring pharmacotherapy Medical condition necessitating therapeutic diet incompatible with MedDiet principles Inability to attend ≥75 % of education sessions

Intervention Mediterranean Diet Education Programme (Weeks 1-4) Format: Four weekly face-to-face group sessions (60 min each) delivered by a registered dietitian trained in behavioural counselling.

Content:

Session 1: MedDiet pyramid, portion guidance, meal timing for shift workers Session 2: Practical meal planning; reading food labels; healthy cafeteria choices Session 3: Strategies to increase fruit, vegetable, legume and whole-grain intake; recipe demonstrations Session 4: Reducing ultra-processed foods, sugar-sweetened beverages and saturated fats; sustaining behaviour change Materials: Printed handbook (pyramid graphic, shopping lists, sample menus), online discussion forum and weekly motivational text messages.

Fidelity: Sessions follow a standardised script; attendance recorded; 10 % of sessions audited by a second dietitian.

Participants receive no meal provision; they are encouraged to apply learned principles during all shifts. No changes are made to hospital food service.

Data Collection and Management Questionnaires are administered electronically via a secure, password-protected platform. Anthropometric measurements are performed in duplicate by trained research staff following WHO protocols. Blood draws coincide with routine occupational health surveillance to minimise burden and cost. Data are de-identified upon entry; only the principal investigator retains the re-identification key in an encrypted file.

Data analysis The analysis of the data collected in the study was performed using the SPSS 21.0 software. Descriptive statistics such as arithmetic mean, frequency, standard deviation, and percentage values were utilized in the analysis. To determine whether the data showed a normal distribution, skewness and kurtosis values were examined, and these values were found to be between -2 and +2, indicating that the data followed a normal distribution. Accordingly, parametric tests were used for comparisons between groups based on demographic information and for examining relationships between scales. To compare the pre- and post-test results of the Mediterranean diet, sleep disorders, and physical activity scales with blood parameters, the Paired-Samples T-Test was used, while comparisons by gender were conducted using the Independent-Samples T-Test. For comparisons across age groups, One-Way ANOVA was performed, and Tukey's test was applied as the post hoc analysis. Additionally, Pearson correlation analysis was conducted to determine the relationships between nurses' Mediterranean diet education and their sleep quality, physical activity levels, blood parameters, and anthropometric measurements.

The internal consistency of the Mediterranean Diet Adherence Scale, developed by Özkan Pehlivanoğlu, Hüseyin Balcıoğlu, and İlhami Ünlüoğlu, was calculated as Cronbach's α = 0.829, indicating a high level of reliability. The Pittsburgh Sleep Quality Index, developed by Buysse et al. in 1989, demonstrated satisfactory internal consistency (Cronbach's α = 0.80), test-retest reliability, and construct validity. In their 2017 systematic review of physical activity assessment in amputees, Piazza, Ferreira, Minsky, Pires, and Silva reported a reproducibility coefficient of ρ = 0.81 (95% CI = 0.79-0.82).

Outcome Measures and Time Points Primary and secondary outcomes were assessed at baseline (Week 0) and after the intervention (Week 8), unless otherwise specified.

The primary outcomes of the study were adherence to the Mediterranean diet and sleep quality. Adherence was measured using the 14-item Mediterranean Diet Adherence Screener (MEDAS), a validated tool for assessing compliance with Mediterranean dietary principles. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI), a widely used self-report instrument for assessing subjective sleep patterns and disturbances.

The secondary outcomes included physical activity level, anthropometric measurements, blood biomarkers, and adverse events. Physical activity was assessed using the International Physical Activity Questionnaire-Short Form (IPAQ-SF). Anthropometric data were collected through standardized procedures: height was measured at baseline using a stadiometer, and weight, body fat percentage, and skeletal muscle mass were evaluated at both time points using the Tanita MC-180 body composition analyzer. Waist and hip circumferences were measured with a non-elastic measuring tape.

Blood biomarkers were assessed via fasting venous blood samples collected and analyzed in the hospital laboratory. Parameters included fasting glucose, insulin, triglycerides, LDL cholesterol, HDL cholesterol, and total cholesterol. The Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) was calculated using fasting glucose and insulin values.

In addition, potential adverse events were monitored continuously throughout the study using a structured questionnaire administered at regular intervals.

Ethical Considerations Ethical approval was obtained from the Bahçeşehir University Scientific Research and Publication Ethics Committee. The study complies with the Declaration of Helsinki and relevant local regulations. Participation is voluntary; nurses may withdraw at any time without affecting employment status or access to occupational health services. The intervention poses minimal risk (education only).

Recruitment begun May 2024 and finished November 2024.

• Study Type: Interventional
• Enrollment (Actual): 130
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey
  • Bodrum
    • Muğla, Bodrum, Turkey
      • Bodrum Acıbadem Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Registered nurse working ≥3 rotating shifts per month at the study hospital
• Age 18-55 years
• Written informed consent

Exclusion Criteria:

• Pregnancy or lactation
• Current participation in another lifestyle or drug trial
• Diagnosed sleep disorder requiring pharmacotherapy
• Medical condition necessitating therapeutic diet incompatible with MedDiet principles
• Inability to attend ≥75 % of education session

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Screening
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Shift working nurses

Behavioral: Mediterranean Diet Education Program; The intervention consists of a 4-week Mediterranean Diet Education Program designed specifically for nurses working rotating shifts. The program included four weekly group sessions, each lasting approximately 60 minutes, delivered in-person by a registered dietitian with training in behavioral change and clinical nutrition. Sessions are interactive and supported by visual and printed educational materials. Participants receive a printed handbook including a food pyramid graphic, portion guides, weekly shopping lists, and sample menus tailored to shift work schedules. They also gain access to a moderated online discussion group and receive weekly motivational text messages to reinforce key messages. No food is provided directly.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
MEDAS Score	Change in Mediterranean Diet Adherence Score (MEDAS) Change in adherence to the Mediterranean diet as measured by the 14-item Mediterranean Diet Adherence Screener (MEDAS). This validated questionnaire assesses the frequency and quality of consumption of key Mediterranean dietary components. Scores range from 0 to 14, with higher scores indicating greater adherence.	Baseline (week 0) and post-intervention (week 8)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Physical Activity	Change in physical activity level as measured by the International Physical Activity Questionnaire - Short Form (IPAQ-SF). The IPAQ-SF estimates weekly energy expenditure (in MET-minutes/week) across domains such as walking, moderate and vigorous activity.	Baseline (week 0), Postintervention (week 8)
BMI Change	Change in BMI calculated as weight (kg) divided by height squared (m²). Weight measured using the Tanita MC-180 body composition analyzer; height measured at baseline with a stadiometer. Body Mass Index (BMI) will be calculated using weight and height measurements. Weight was measured in kilograms (kg) and height was measured in meters (m). BMI was computed as weight (kg) divided by the square of height (m²) and reported in kg/m² as a single outcome measure.	Baseline (Week 0) and Post-Intervention (Week 8)
Sleep Quality	Change in sleep quality as measured by the Pittsburgh Sleep Quality Index (PSQI). This 19-item self-report tool assesses subjective sleep quality, latency, duration, efficiency, disturbances, and daytime dysfunction. Scores range from 0 to 21; higher scores indicate poorer sleep quality.	baseline (week 0) postintervention (week 8)
Waist Hip Ratio	Change in waist-to-hip ratio (WHR), calculated by dividing waist circumference by hip circumference. Measurements obtained using a non-elastic measuring tape according to WHO standards.	Baseline (Week 0) and Post-Intervention (Week 8)
Change in Blood Results Profile	Change in fasting blood glucose levels, measured via venous blood draw in a hospital laboratory. Changes in fasting insulin levels and HOMA-IR (Homeostatic Model Assessment of Insulin Resistance) Changes in serum lipid parameters, including total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides, measured from fasting venous blood samples.	Baseline (Week 0) and Post-Intervention (Week 8)

Collaborators and Investigators

• Sponsor: Bahçeşehir University

Publications and helpful links

General Publications

• Sun M, Feng W, Wang F, Li P, Li Z, Li M, Tse G, Vlaanderen J, Vermeulen R, Tse LA. Meta-analysis on shift work and risks of specific obesity types. Obes Rev. 2018 Jan;19(1):28-40. doi: 10.1111/obr.12621. Epub 2017 Oct 4.
• Franzago M, Alessandrelli E, Notarangelo S, Stuppia L, Vitacolonna E. Chrono-Nutrition: Circadian Rhythm and Personalized Nutrition. Int J Mol Sci. 2023 Jan 29;24(3):2571. doi: 10.3390/ijms24032571.

Study record dates

Study Major Dates

• Study Start (Actual): May 8, 2024
• Primary Completion (Actual): November 9, 2024
• Study Completion (Actual): November 9, 2024

Study Registration Dates

• First Submitted: July 31, 2025
• First Submitted That Met QC Criteria: August 13, 2025
• First Posted (Estimated): August 14, 2025

Study Record Updates

• Last Update Posted (Estimated): August 14, 2025
• Last Update Submitted That Met QC Criteria: August 13, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Keywords: Circadian rhythm; Lifestyle modification; Metabolic health; Nutritional intervention; Workplace wellness
• Additional Relevant MeSH Terms: Endocrine System Diseases; Vascular Diseases; Metabolic Diseases; Glucose Metabolism Disorders; Diabetes Mellitus; Insulin Resistance; Hyperinsulinism; Arteriosclerosis; Arterial Occlusive Diseases; Diabetes Mellitus, Type 2; Cardiovascular Diseases; Metabolic Syndrome; Atherosclerosis
• Other Study ID Numbers: E-85646034-604.01-81176

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared due to ethical and privacy considerations.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No