Skip to main content
OpenTrials
Recruiting

NCT Number: NCT07189637

The Combined Effect of the Mediterranean Diet and Intermittent Fasting on Hypertension

Hypertension (HT) is an important risk factor for cardiovascular diseases (CVD) and death. Approximately 16.9 million people in Turkey have HT. Nutritional habits play an important role in the development of HT. DASH (Dietary Approaches to Stop Hypertension) and the Mediterranean diet (MD) have been found to be effective in lowering blood pressure and reducing cardiometabolic risks. The DASH diet stands out with its low sodium, saturated fat, simple sugar and cholesterol content, while it is rich in fiber, potassium, magnesium and anti-inflammatory components. The MD is based on healthy foods such as olive oil, vegetables, fruits, fish and nuts, and contains antioxidants and healthy fatty acids. This study will investigate whether the sodium-restricted MD can offer a model comparable to DASH. In addition, the effects of the intermittent fasting diet (IFD) model alone and in combination with the MD on blood pressure will be examined. It has been observed that IFD reduces blood pressure by reducing energy intake and acting on the autonomic nervous system. The aim of this project is to evaluate the effects of MD, IFD and both of them on hypertension and to present a new and original approach in this field.

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Hypertension Behavior Cardiovascular Diseases Fasting Feeding Behavior Intermittent Fasting Vascular Diseases

Age range

40 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Medipol Mega University Hospital

Istanbul, 34214, Turkey (Türkiye)

Location status: Recruiting

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Newly diagnosed hypertension patients
  • Individuals with blood pressure >140/90 mmHg
  • Individuals with a body mass index (BMI) in the range of 18.5-25 kg/m²
  • Individuals aged 40-65 years

Exclusion criteria

Participants will be excluded if they have any of the following:

  • Type 2 Diabetes Mellitus
  • Type 1 Diabetes Mellitus
  • Cardiovascular disease
  • Liver disease
  • Kidney disease
  • Gastrointestinal disease
  • Respiratory disease
  • Psychiatric disorders
  • Women who are pregnant or breastfeeding
  • Severe food allergies
  • Current smokers or individuals consuming alcohol regularly
  • History of major surgery within the last 6 months

Treatment and study plan

Face-to-face nutrition education

Other

All participants will receive face-to-face nutrition education from specialist dietitians in accordance with the principles of nutrition for hypertension. Nutrition education will be provided through prepared brochures. The brochures will be given to participants as gifts. Nutrition education will cover topics such as hypertension and nutrition, nutrients, the importance of micronutrients, foods containing salt, reading labels, limiting salt consumption, healthy fat consumption, fibre consumption, water consumption, and healthy cooking methods.

Intermittent Fasting Diet

Other

Training will be provided to all participants through a food and nutrition photo catalogue so that portions can be recorded correctly and within standard limits when keeping a food diary. Participants will restrict their food intake to a 16-hour period by applying the 16/8 Intermittent Fasting Diet model and will eat and drink whatever they want during the remaining 8 hours. During this 16-hour period, they will consume non-energy drinks consisting of water, unsweetened tea, unsweetened herbal teas and black coffee. It will be recommended that intermittent fasting be maintained from 6:00 p.m. to 10:00 a.m. However, participants may also choose other 16-hour periods, such as 7:00 p.m. to 11:00 a.m. or 8:00 p.m. to 12:00 p.m. Participants will be given a tracking chart to record the first and last times they consume food or energy-containing beverages during the day, and their adherence to the diet will be monitored based on their declarations.

Mediterranean Diet

Other

Training will be provided to all participants through a food and nutrition photo catalogue to ensure that portions are recorded correctly and within standard limits when keeping a food diary. In addition, the dietician will provide this group with a diet plan calculated for energy, macro and micro nutrients, which will be different each week for the first four follow-ups. The diet plans provided will be prepared in accordance with the Mediterranean Diet food pyramid. Participants' energy requirements will be calculated using the Schofield Equation for basal metabolic rate, with adjustments made according to their physical activity levels. Energy requirements will be met by 45-50% from carbohydrates, 15-20% from protein, and 25-35% from fats.

Primary outcomes

  1. Blood pressure

    Time frame: At enrollment, 1 week later than enrollment, 2 weeks later than enrollment, 3 weeks later than enrollment, 4 weeks later than enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    The participants' blood pressure will be measured six times in this research. Blood pressure measurements will be taken by a trained physician in accordance with standard measurement protocols. Measurements will be taken after a 5-minute rest period, with the patient seated, using an automatic blood pressure monitor with the correct cuff size applied to the arm. Two consecutive measurements will be taken for each patient, with at least 1 minute between measurements. The average of the two measurements obtained will be used in the analyses.

    The following points will be taken into consideration during the measurements.

    • Patients should not have smoked, consumed caffeine, or exercised in the last 30 minutes
    • During the measurement, the patient should be leaning back with their feet flat on the floor
    • The arm being measured should be supported at heart level Blood pressure values will be evaluated according to the 2023 ESC/ESH hypertension guidelines.

Secondary outcomes

  1. Height in cm

    Time frame: At enrollment, 1 week later than enrollment, 2 weeks later than enrollment, 3 weeks later than enrollment, 4 weeks later than enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    Height measurement will be taken by a specialist dietician. It will be performed in accordance with the measurement techniques and standards recommended by the International Society for the Advancement of Kinanthropometry. Participants' heights will be measured barefoot using a stadiometer with an accuracy of 0.01 m.

  2. Body weight in kg

    Time frame: At enrollment, 1 week later than enrollment, 2 weeks later than enrollment, 3 weeks later than enrollment, 4 weeks later than enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    Body weight measurement will be taken by a specialist dietician. It will be performed in accordance with the measurement techniques and standards recommended by the International Society for the Advancement of Kinanthropometry. Body weight and body composition will be measured using a body composition analyser with a precision of 0.1 kg. The participants' clothing weight (1.0 kg) will be recorded on the analyser before measurement. Measurements will be taken barefoot and with participants wearing light clothing. Metal objects on participants will be removed.

  3. Body Mass Index (BMI) in kg/m²

    Time frame: At enrollment, 1 week later than enrollment, 2 weeks later than enrollment, 3 weeks later than enrollment, 4 weeks later than enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    Body Mass Index (BMI) will be used to assess whether an individual's body weight is appropriate for their height. It is calculated by dividing a person's body weight, measured in kilograms (kg), by the square of their height, measured in meters (m). Since height will be measured in centimeters (cm), it will first be converted into meters. This will be done by dividing the height in centimeters by 100.

  4. Waist circumference in cm

    Time frame: At enrollment, 1 week later than enrollment, 2 weeks later than enrollment, 3 weeks later than enrollment, 4 weeks later than enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    Waist circumference: Waist circumference will be taken by a specialist dietician. It will be measured at the narrowest point of the waist with the individual standing upright and without any clothing around the waist. Measurements will be taken with a tape measure, ensuring it is in contact with the skin without applying excessive pressure.

  5. Fasting plasma glucose in mg/dL

    Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    This will be obtained from blood tests. Reference values: 70-99 mg/dL

  6. HbA1c in %

    Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    This will be obtained from blood tests. Reference values: < 5.7% (normal), 5.7-6.4% (prediabetes), ≥ 6.5% (diabetes)

  7. Insulin in µU/mL

    Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    This will be obtained from blood tests. Reference values: 2-25 µU/mL

  8. Triglycerides in mg/dL

    Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    This will be obtained from blood tests. Reference values: < 150 mg/dL

  9. HDL cholesterol in mg/dL

    Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    This will be obtained from blood tests. Reference values:

    Men: ≥ 40 mg/dL Women: ≥ 50 mg/dL

  10. LDL cholesterol in mg/dL

    Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    This will be obtained from blood tests. Reference values: < 100 mg/dL

  11. Total cholesterol in mg/dL

    Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    This will be obtained from blood tests. Reference values: < 200 mg/dL

  12. Urea in mg/dL

    Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    This will be obtained from blood tests. Reference values: 7-20 mg/dL

  13. Creatinine in mg/dL

    Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    This will be obtained from blood tests. Reference values:

    Men: 0.7-1.3 mg/dL Women: 0.6-1.1 mg/dL

  14. Sodium in mmol/L

    Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    This will be obtained from blood tests. Reference values: 135-145 mmol/L

  15. Potassium in mmol/L

    Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    This will be obtained from blood tests. Reference values: 3.5-5.0 mmol/L

  16. hs-CRP in mg/L

    Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    This will be obtained from blood tests. Reference values: < 1 mg/L (low cardiovascular risk), 1-3 mg/L (intermediate risk), > 3 mg/L (high risk)

  17. ALT in U/L

    Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    This will be obtained from blood tests. Reference values: Men: < 41 U/L; Women: < 31 U/L

  18. AST in U/L

    Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    This will be obtained from blood tests. Reference values: Men: < 40 U/L; Women: < 32 U/L

  19. GGT in U/L

    Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment

    This will be obtained from blood tests. Reference values: Men: 8-61 U/L; Women: 5-36 U/L

Interested in participating?

Recruiting

Interested in participating?

Request Info

Sponsors and collaborators

Lead sponsor

Nadide Gizem Tarakci Filiz

Other

Collaborators

  • Fenerbahce University
  • Istanbul Medipol University Hospital
  • Medipol University

Registry information

Important dates

Study start
2025
Primary completion
2026
Study completion
2027
First posted
Sep 24, 2025
Registry last updated
Sep 25, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.