Implementation of a Mediterranean Diet Program for Overweight or Obese Pregnant Women in a Low-resource Clinical Setting (MedDiet)

The purpose of this Pilot randomized clinical Trial is to compare two healthy diet styles during pregnancy. Patients between 8 and 16 weeks of gestation who agree to participate will be randomly assigned (like flipping a coin) to either receive routine healthy diet advice and counseling, or to receive advice and counseling for the Mediterranean style diet. Our current routine healthy diet program follows the recommendations provided by the American College of Obstetricians and Gynecologists (ACOG). It recommends the consumption of grains, fruits, vegetables, protein foods, and dairy foods during pregnancy. The Mediterranean diet (MedDiet) is a well-known healthy diet that consists of a large amount of plant-based foods such as fruits, vegetables, beans, and nuts with olive oil as the principal source of fat. Dairy, fish, and poultry are consumed in moderation and red meat only eaten occasionally. Throughout their pregnancy, participants will receive free food and be assessed to determine adherence to the diet and receive counseling to reinforce diet recommendations.

Study Overview

• Status: Completed
• Conditions: Diet, Healthy; Gestational Weight Gain
• Intervention / Treatment: Behavioral: ACOG-based Dietary Program; Behavioral: MedDiet Program

Detailed Description

The Mediterranean diet (MedDiet) is a well-known healthy diet that consists of a large amount of plant-based foods such as fruits, vegetables, beans, and nuts with extra virgin olive oil (EVOO) as the principal source of fat. Dairy, fish, and poultry are consumed in moderation and red meat only eaten occasionally. A growing body of evidence demonstrates that outside of pregnancy, the MedDiet is associated with a reduction of cardiovascular disease, diabetes, metabolic syndrome, and certain cancers. However, the potential clinical benefits of MedDiet in pregnancy are understudied with most data originating from clinical trials in Europe. Proper nutrition during pregnancy has multiple health benefits. A mother eating a healthy diet has a higher probability of meeting the demands required for a normal fetal development. In addition, she is more likely to achieve the recommended gestational weight gain thereby reducing the risk of pregnancy-related complications. Finally, a healthy diet is associated with a reduction of chronic conditions such as cardiovascular disease and diabetes later in life for both the mother and the infant.

• Study Type: Interventional
• Enrollment (Actual): 41
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • North Carolina
    • Charlotte, North Carolina, United States, 28207
      • Atrium Health Myers Park OB/GYN

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Viable singleton pregnancy in the first trimester (6 0/7- 16 6/7 weeks); includes twins reduced to singleton spontaneously or vanishing twin syndrome
• BMI ≥ 25.0 kg/m2; calculated by dividing maternal weight in kilograms by height in meters squared using a calibrated scale and standard metric measure
• Confirmed intrauterine pregnancy by ultrasound exam (6-16 weeks)
• Age 18 years or older
• Primary language of English or Spanish

Exclusion Criteria:

• BMI < 25.0 kg/m2
• Known pre-pregnancy diabetes
• Hemoglobin glycosylated (A1C) > 5.7% at first prenatal visit
• Pre-pregnancy hypertensive disease
• Non-viable pregnancy
• Known allergies to an essential component(s) of MedDiet
• Inability to read or write in primary language
• Mental incapacity to make medical decisions

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: American College of Obstetricians and Gynecologists (ACOG)-based Dietary Program; Routine dietary counseling program	Behavioral: ACOG-based Dietary Program; Following ACOG recommendation, subjects allocated to the ACOG-based Dietary Program group, will receive routine counseling on healthy eating. This will include advice on the consumption of grains, fruits, vegetables, protein, and dairy foods recommended during pregnancy. Diet adherence will be assessed using an 18 question questionnaire. Participants will receive 6, free traditional healthy meals every 3 weeks between enrollment and until the subject is approximately 38 weeks pregnant. In addition, participants will receive canola oil and healthy snacks during their enrollment visit and during their routine 26-30 week prenatal visit.
Experimental: Mediterranean Diet (MedDiet) Program; Well-known healthy diet that consists of a large amount of plant-based foods such as fruits, vegetables, beans, and nuts with extra virgin olive oil (EVOO) as the principal source of fat. Dairy, fish, and poultry are consumed in moderation and red meat only eaten occasionally.	Behavioral: MedDiet Program; Subjects allocated to the MedDiet Program group will receive counseling based on the principles of the traditional MedDiet with a focus on a general change in diet instead of micronutrients or macronutrients. Diet adherence will be assessed using a 14 question questionnaire. Participants will receive 6, free traditional MedDiet meals every 3 weeks between enrollment and until the subject is approximately 38 weeks pregnant. In addition, participants will receive olive oil and nuts during their enrollment visit and during their routine 26-30 week prenatal visit.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diet Adherence Assessment Scores Continuous	The Routine Healthy Diet Assessment Questionnaire consists of 15 items. Each item is scored as 1 for adherence and 0 for non-adherence, with some items having trimester-specific scoring. The total score is the sum of all items, ranging from 0 (no adherence) to 15 (full adherence). Higher scores indicate better adherence to the routine healthy diet .The MedDiet Assessment Questionnaire consists of 17 items. Each item is scored as 1 for adherence and 0 for non-adherence. The total score is the sum of all items, ranging from 0 (no adherence) to 17 (full adherence). Higher scores indicate better adherence to the Mediterranean diet.	week 38

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gestational Weight Gain (GWG)	Total GWG will be calculated by subtracting the participant's weight (lbs.) at the initial prenatal visit from the weight (lbs.) at time of the delivery or at the last prenatal visit. GWG in the first trimester (6-13 weeks), second trimester (14-26 weeks), and third trimester (27-40 weeks) will also be calculated. Calibrated weight scales will be used at our clinic and at the hospital. Compliance rate of GWG based on Institute of Medicine (IOM) guidelines for overweight and obese women will be compared between the MedDiet and the control group.	week 40
Cardiometabolic Biomarkers - Hemoglobin A1C Levels	Hypothesize that consuming the Mediterranean diet (MedDiet) may be associated with improved cardiometabolic biomarkers during pregnancy. Specifically, MedDiet might help reduce the physiological rise in lipids, enhance insulin sensitivity, and lower markers of subclinical inflammation, such as C-reactive protein (CRP). Pregnancy is usually marked by increased levels of total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides, especially in the second and third trimesters, along with increased insulin resistance. This study aims to determine whether MedDiet influences these biomarkers. Maternal lipid profiles, random glucose levels, hemoglobin A1C, and CRP will be measured at baseline (first or second trimester) and between 26-30 weeks of gestation among participants in both the intervention and control groups. Lab samples will be collected during routine blood draws for prenatal care.	Week 30
Cardiometabolic Biomarkers - C-reactive Protein (CRP) Levels	Consumption of MedDiet is associated with lower levels of total cholesterol, reduces insulin resistance preventing type 2 diabetes and Gestational diabetes mellitus (GDM), and reduces markers of subclinical inflammation such as C-reactive protein (CRP). Pregnancy is characterized by increased levels of total cholesterol, low-density lipoprotein (LDP), high-density lipoprotein (HDL), and triglycerides, especially in the second and third trimester, and pregnancy is a state of increased insulin resistance. There is limited knowledge about the effect of MedDiet on cardiometabolic biomarkers during pregnancy. Maternal lipid profile, random glucose level, hemoglobin A1C, and CRP levels will be compared at baseline (first or early second trimester) and at 26-30 weeks of gestation among participants in the intervention and the control groups. The labs will be obtained at the same time of scheduled blood draws for routine prenatal labs.	Week 30
Cardiometabolic Biomarkers - Triglycerides	Consumption of MedDiet is associated with lower levels of total cholesterol, reduces insulin resistance preventing type 2 diabetes and Gestational diabetes mellitus (GDM), and reduces markers of subclinical inflammation such as C-reactive protein (CRP). Pregnancy is characterized by increased levels of total cholesterol, low-density lipoprotein (LDP), high-density lipoprotein (HDL), and triglycerides, especially in the second and third trimester, and pregnancy is a state of increased insulin resistance. There is limited knowledge about the effect of MedDiet on cardiometabolic biomarkers during pregnancy. Maternal lipid profile, random glucose level, hemoglobin A1C, and CRP levels will be compared at baseline (first or early second trimester) and at 26-30 weeks of gestation among participants in the intervention and the control groups. The labs will be obtained at the same time of scheduled blood draws for routine prenatal labs.	Week 30
Cardiometabolic Biomarkers - Glucose Level	Consumption of MedDiet is associated with lower levels of total cholesterol, reduces insulin resistance preventing type 2 diabetes and Gestational diabetes mellitus (GDM), and reduces markers of subclinical inflammation such as C-reactive protein (CRP). Pregnancy is characterized by increased levels of total cholesterol, low-density lipoprotein (LDP), high-density lipoprotein (HDL), and triglycerides, especially in the second and third trimester, and pregnancy is a state of increased insulin resistance. There is limited knowledge about the effect of MedDiet on cardiometabolic biomarkers during pregnancy. Maternal lipid profile, random glucose level, hemoglobin A1C, and CRP levels will be compared at baseline (first or early second trimester) and at 26-30 weeks of gestation among participants in the intervention and the control groups. The labs will be obtained at the same time of scheduled blood draws for routine prenatal labs.	Week 30
Cardiovascular Parameters - Blood Pressure (BP) Values (Diastolic)	MedDiet is associated with reduction of blood pressure (BP) in non-pregnant adult overweight or obese women. Physiological changes of blood pressure (BP) during pregnancy are characterized by reduction of BP in the second trimester with return to the pre-pregnancy level late in the third trimester and postpartum period. Heart rate (HR) increases by 20% to 25% over baseline during gestation. Maternal BP and HR will be obtained by a calibrated automated oscillometric device during prenatal visits from the first to the third trimesters following the standardized technique established in our clinic. Trends of BP and HR throughout gestation will be compared among women allocated in the intervention and the control groups.	Week 16
Cardiovascular Parameters - Blood Pressure (BP) Values (Diastolic)	MedDiet is associated with reduction of blood pressure (BP) in non-pregnant adult overweight or obese women. Physiological changes of blood pressure (BP) during pregnancy are characterized by reduction of BP in the second trimester with return to the pre-pregnancy level late in the third trimester and postpartum period. Heart rate (HR) increases by 20% to 25% over baseline during gestation. Maternal BP and HR will be obtained by a calibrated automated oscillometric device during prenatal visits from the first to the third trimesters following the standardized technique established in our clinic. Trends of BP and HR throughout gestation will be compared among women allocated in the intervention and the control groups.	Week 24
Cardiovascular Parameters - Blood Pressure (BP) Values (Diastolic)	MedDiet is associated with reduction of blood pressure (BP) in non-pregnant adult overweight or obese women. Physiological changes of blood pressure (BP) during pregnancy are characterized by reduction of BP in the second trimester with return to the pre-pregnancy level late in the third trimester and postpartum period. Heart rate (HR) increases by 20% to 25% over baseline during gestation. Maternal BP and HR will be obtained by a calibrated automated oscillometric device during prenatal visits from the first to the third trimesters following the standardized technique established in our clinic. Trends of BP and HR throughout gestation will be compared among women allocated in the intervention and the control groups.	Week 30
Cardiovascular Parameters - Blood Pressure (BP) Values (Diastolic)	MedDiet is associated with reduction of blood pressure (BP) in non-pregnant adult overweight or obese women. Physiological changes of blood pressure (BP) during pregnancy are characterized by reduction of BP in the second trimester with return to the pre-pregnancy level late in the third trimester and postpartum period. Heart rate (HR) increases by 20% to 25% over baseline during gestation. Maternal BP and HR will be obtained by a calibrated automated oscillometric device during prenatal visits from the first to the third trimesters following the standardized technique established in our clinic. Trends of BP and HR throughout gestation will be compared among women allocated in the intervention and the control groups.	Week 38
Cardiovascular Parameters - Blood Pressure (BP) Values (Systolic)	MedDiet is associated with reduction of blood pressure (BP) in non-pregnant adult overweight or obese women. Physiological changes of blood pressure (BP) during pregnancy are characterized by reduction of BP in the second trimester with return to the pre-pregnancy level late in the third trimester and postpartum period. Heart rate (HR) increases by 20% to 25% over baseline during gestation. Maternal BP and HR will be obtained by a calibrated automated oscillometric device during prenatal visits from the first to the third trimesters following the standardized technique established in our clinic. Trends of BP and HR throughout gestation will be compared among women allocated in the intervention and the control groups.	Week 16
Cardiovascular Parameters - Blood Pressure (BP) Values (Systolic)	MedDiet is associated with reduction of blood pressure (BP) in non-pregnant adult overweight or obese women. Physiological changes of blood pressure (BP) during pregnancy are characterized by reduction of BP in the second trimester with return to the pre-pregnancy level late in the third trimester and postpartum period. Heart rate (HR) increases by 20% to 25% over baseline during gestation. Maternal BP and HR will be obtained by a calibrated automated oscillometric device during prenatal visits from the first to the third trimesters following the standardized technique established in our clinic. Trends of BP and HR throughout gestation will be compared among women allocated in the intervention and the control groups.	Week 24
Cardiovascular Parameters - Blood Pressure (BP) Values (Systolic)	MedDiet is associated with reduction of blood pressure (BP) in non-pregnant adult overweight or obese women. Physiological changes of blood pressure (BP) during pregnancy are characterized by reduction of BP in the second trimester with return to the pre-pregnancy level late in the third trimester and postpartum period. Heart rate (HR) increases by 20% to 25% over baseline during gestation. Maternal BP and HR will be obtained by a calibrated automated oscillometric device during prenatal visits from the first to the third trimesters following the standardized technique established in our clinic. Trends of BP and HR throughout gestation will be compared among women allocated in the intervention and the control groups.	Week 30
Cardiovascular Parameters - Blood Pressure (BP) Values (Systolic)	MedDiet is associated with reduction of blood pressure (BP) in non-pregnant adult overweight or obese women. Physiological changes of blood pressure (BP) during pregnancy are characterized by reduction of BP in the second trimester with return to the pre-pregnancy level late in the third trimester and postpartum period. Heart rate (HR) increases by 20% to 25% over baseline during gestation. Maternal BP and HR will be obtained by a calibrated automated oscillometric device during prenatal visits from the first to the third trimesters following the standardized technique established in our clinic. Trends of BP and HR throughout gestation will be compared among women allocated in the intervention and the control groups.	Week 38

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Initial Heartrate	MedDiet is associated with reduction of blood pressure (BP) in non-pregnant adult overweight or obese women. Physiological changes of blood pressure (BP) during pregnancy are characterized by reduction of BP in the second trimester with return to the pre-pregnancy level late in the third trimester and postpartum period. Heart rate (HR) increases by 20% to 25% over baseline during gestation. Maternal BP and HR will be obtained by a calibrated automated oscillometric device during prenatal visits from the first to the third trimesters following the standardized technique established in our clinic. Trends of BP and HR throughout gestation will be compared among women allocated in the intervention and the control groups.	Week 16
Number of Adverse Pregnancy Outcomes - Gestational Hypertension, Pre-eclampsia, Eclampsia	examine the most common Adverse Pregnancy Outcomes (APO) associated with overweight and obesity: preeclampsia, eclampsia, gestational hypertension, gestational diabetes mellitus, preterm birth, cesarean delivery, large for gestational age infant.	week 40
Number of Adverse Pregnancy Outcomes (APO) Gestational Diabetes Mellitus	examine the most common Adverse Pregnancy Outcomes (APO) associated with overweight and obesity: preeclampsia, eclampsia, gestational hypertension, gestational diabetes mellitus, preterm birth, cesarean delivery, large for gestational age infant.	week 40
Number of Adverse Pregnancy Outcomes (APO) Preterm Birth	examine the most common Adverse Pregnancy Outcomes (APO) associated with overweight and obesity: preeclampsia, eclampsia, gestational hypertension, gestational diabetes mellitus, preterm birth, cesarean delivery, large for gestational age infant.	week 36
Number of Adverse Pregnancy Outcomes (APO) Cesarean Delivery	examine the most common Adverse Pregnancy Outcomes (APO) associated with overweight and obesity: preeclampsia, eclampsia, gestational hypertension, gestational diabetes mellitus, preterm birth, cesarean delivery, large for gestational age infant.	week 40
Number of Adverse Pregnancy Outcomes (APO) Large for Gestational Age Infant	examine the most common Adverse Pregnancy Outcomes (APO) associated with overweight and obesity: preeclampsia, eclampsia, gestational hypertension, gestational diabetes mellitus, preterm birth, cesarean delivery, large for gestational age infant.	week 40

Collaborators and Investigators

• Sponsor: Wake Forest University Health Sciences
• Collaborators: National Center for Advancing Translational Sciences (NCATS)
• Investigators: Principal Investigator: Julio Mateus Nino, MD, PhD, Wake Forest University Health Sciences

Study record dates

Study Major Dates

• Study Start (Actual): August 31, 2023
• Primary Completion (Actual): November 30, 2024
• Study Completion (Actual): July 10, 2025

Study Registration Dates

• First Submitted: May 11, 2023
• First Submitted That Met QC Criteria: May 11, 2023
• First Posted (Actual): May 22, 2023

Study Record Updates

• Last Update Posted (Actual): December 8, 2025
• Last Update Submitted That Met QC Criteria: December 4, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Keywords: Overweight; Obese; Mediterranean Diet; Pregnant Women
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Body Weight Changes; Weight Gain; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Gestational Weight Gain; Overweight; Obesity
• Other Study ID Numbers: IRB00096969; UL1TR001420 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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