The aim of our study is to compare adherence to the MedDiet between women who received a nutritional educational intervention during a 6-month follow-up and those who did not receive an intervention. Additionally, investigators will examine how this intervention affects mothers' nutritional status, anthropometric measures, and mental health. The objectives of this study are: 1. To assess the impact of an educational intervention on MedDiet adherence among lactating women aged 18-40 years in Jordan over a six-month follow-up period. 2. To explore the relationship between MedDiet adherence, obesity, and mental health among lactating women aged 18-40 years in Jordan during the same period.

This study is a prospective, three-arm, parallel-group interventional trial designed to assess the effect of nutritional education on dietary adherence and mental health-related outcomes among lactating women in Jordan. Participants will be followed for 6 months, with assessments at baseline, 3 months, and 6 months. Women will be recruited from maternal and child health vaccination clinics.

After recruitment, participants will be randomly assigned to one of three study groups: (1) intervention group, (2) brochure group, or (3) control group.

Data collection will occur at three time points (baseline, 3 months, and 6 months) using validated instruments. Dietary intake and adherence will be measured using a structured Mediterranean Diet Score (MDS), the Mediterranean Diet Adherence Screener (MEDA), and a culturally adapted Food Frequency Questionnaire (FFQ). Nutritional status will be assessed through anthropometric measurements. Mental health outcomes will be measured using standardized and validated scales for depression, anxiety, stress, fatigue, and sleep quality. All data will be collected through interviewer-administered questionnaires conducted by trained research staff.

A. Questionnaires:

Validated Arabic version of:

• MEDAS: A 14-item Mediterranean Diet Adherence Screener (14-MEDAS) will be used to assess the adherence of eligible participants to MedDiet
• Food Frequency questionnaire: The questionnaire assesses habitual dietary intake by questioning the frequency with which food items are consumed over one week. It is adjusted in a cultural context; foods not typically used in the Jordanian diet are omitted, while foods typically used are added.
• A diet quality questionnaire, the food-based diet quality index, was created by synthesizing current nutrition knowledge. The questionnaire includes 14 "healthy" and 7 "unhealthy" food components known to affect health and prevent major diet-related diseases.
• Depression, Anxiety, and Stress Scale-21 Items (DASS-21) is a set of three self-report scales developed to measure the emotional states of depression, anxiety, and stress that can effectively assess mental health symptoms for individuals.
• Modified Fatigue Impact Scale (MFIS): The MFIS is a modified version of the FIS that measures physical, cognitive, and psychosocial fatigue. Participants rate the impact of fatigue on their lives over the past 4 weeks on a scale of 0 (no problem) to 4 (extreme problem).
• The Pittsburgh Sleep Quality Index (PSQI) measures general sleep quality and is a recommended questionnaire for studying global sleep and insomnia symptoms.
• The Beck Depression Inventory (BDII): This depression self-report measure has been extensively researched and used in clinical and non-clinical populations. It has strong psychometric properties and is widely implemented in depression-related research.
• SF-36 ARABIC

B. Educational Intervention:

The educational intervention will include the importance and health benefits of MedDiet, mental health, good food sources, and lifestyle practices to maintain good nutritional status and mental health during lactation, with regular reminders about the importance of a healthy diet. These reminders will be communicated through channels such as text messages or WhatsApp. The second group will receive only the brochure. The brochure will include the definition and components of MedDiet, its health benefits, food sources, food alternatives rich in minerals such as iron, calcium, and B vitamins, and the importance of healthy lifestyles, including increasing physical activity and avoiding smoking. Lastly, the third group will be the control group. Participants will not receive educational interventions or brochures. However, due to ethical considerations, the control group will receive the education and brochure after completing the study.

Statistical analysis The database will be built in Microsoft Excel, with duplicate entries to verify data consistency. Data processing and analysis will be performed using SPSS 24 (IBM, NY, USA).

Descriptive statistics and correlations for all quantitative and categorical study variables are calculated at baseline and at the end of the study to present the prevalence of depression, anxiety, and stress severity. Appropriate descriptive statistics such as percentages, means, and standard deviation summarize the data depending on the variable type. The Shapiro-Wilk test will be applied to assess data normality. Data are described using means (SD) and percentages. The student's t-test will be used to compare the means and medians of independent variables between groups; Pearson's Chi-Square test will be used for categorical data to test for association and probability, especially the relationship between sociodemographic variables, nutritional status, and the severity of depression, anxiety, and stress. Moreover, the significance level was set at p < 0.05, along with logistic regression, to identify the determinants of the severity of depression, anxiety, and stress among pregnant women attending the clinics. For ordinal regression modeling, severity is coded as normal = 0, mild = 1, moderate = 2, and severe = 3. The multivariable ordinal logistic regression model includes Variables statistically significant at P ≤ 0.05 in the bivariate analyses.

Inclusion Criteria:

• Lactating women aged 18-40.

Exclusion Criteria:

• Lactating women aged below 18 or above 40
• Lactating women diagnosed with mental diseases
• Lactating women who were already on supplementation for managing deficiencies such as iron, B12, and vitamin D, or hormonal disturbances, mainly thyroxine.