Mediterranean Diet and Blood Sugar Study

NCT ID: NCT07229781

Last Updated: 2025-11-17

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 74 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2026-03-01
• Study Completion Date: 2028-04-30

Brief Summary

The purpose of this research study is to determine if a healthy Mediterranean diet containing one medium potato/day has equivalent or non-different effects on risk factors for type 2 diabetes and heart disease compared to a healthy Mediterranean diet without potatoes in adults with prediabetes. Participants will be randomly assigned to one of the test diets and be asked to consume this diet for 12 weeks (84 days). Testing will be conducted at the beginning and end of the study.

Detailed Description

This is a 12-week, 2-arm parallel, randomized controlled feeding trial. Participants will be randomized to either a Mediterranean-style diet that includes 1 medium potato/day/2000 kcal replacing some grains , or a traditional-style Mediterranean dietary pattern without potatoes. All food will be provided for the 12-week study duration.

Conditions

Prediabetes

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: SINGLE

Study Groups

Mediterranean-style diet with potato (MED-P)

Mediterranean-style diet that includes 1 medium potato/day/2000 kcal replacing some grains

Group Type: EXPERIMENTAL

Mediterranean-style diet with potatoes

Intervention Type: OTHER

The diet will contain 1 medium potato/day/2000 kcal

Traditional-style Mediterranean dietary pattern (MED)

A traditional-style Mediterranean diet that does not contain potatoes (potatoes are not a defining feature of this diet) and is higher in grains.

Group Type: ACTIVE_COMPARATOR

Traditional-style Mediterranean diet

Intervention Type: OTHER

Traditional-style Mediterranean diet higher in grains

Interventions

Mediterranean-style diet with potatoes

The diet will contain 1 medium potato/day/2000 kcal

Intervention Type: OTHER

Traditional-style Mediterranean diet

Traditional-style Mediterranean diet higher in grains

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Age 25-65 years
• Prediabetes assessed by an HbA1c of 5.7-6.4% or fasting glucose 100-125 mg/dL at screening
• BMI 25-40 kg/m2 at screening

Exclusion Criteria

• HbA1c ≥6.5% at screening
• LDL-C (calculated with the Martin-Hopkins equation) ≥190 mg/dL at screening
• Hemoglobin <13.2 g/dL at screening
• Fasting triglycerides >350 mg/dL at screening

-≥10% change in body weight within the 6 months prior to enrollment

• Blood pressure >140/90 mmHg at screening
• Type 1 or type 2 diabetes
• Prescription of anti-hypertensive, lipid-lowering, or glucose-lowering drugs
• Intake of supplements that affect the outcomes of interest (i.e., lipid, blood pressure, or glucose lowering; vitamin C or multi-vitamins containing vitamin C) and are unwilling to cease during the study period.
• History of liver, kidney, or autoimmune disease
• Prior cardiovascular event (e.g., stroke, heart attack)
• Current pregnancy or intention of pregnancy within the next 6 months
• Lactation within the prior 6 months
• Allergy/intolerance/sensitivity/dislike of any foods in the study menus
• Antibiotic use within the prior 1 month
• Oral steroid use within the prior 1 month
• Use of tobacco or nicotine-containing products within the past 6 months
• History of cancer at any site within the past 10 years (eligible if ≥10 years without recurrence) or non-melanoma skin cancer within the past 5 years (eligible if ≥5 years without recurrence)
• Participation in another clinical trial within 60 days of baseline
• Currently following a restricted or weight-loss diet
• Prior bariatric surgery
• Intake of >14 alcoholic drinks/week and/or not willing to avoid alcohol consumption for 48 hours prior to test visits
• Principal Investigator discretion related to the potential participant's ability to adhere to the study requirements, including being able to come to attend visits
• Does not speak and/or understand English
• Unwilling to refrain from donating blood during the study
• Weight <110 lb

• Minimum Eligible Age: 25 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Alliance for Potato Research & Education

UNKNOWN

Sponsor Role: collaborator

Penn State University

OTHER

Sponsor Role: lead

Responsible Party

Kristina Petersen PhD, APD, FAHA

Associate Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Central Contacts

Kristina Petersen, PhD

Role: CONTACT

kup63@psu.edu

814-865-7206

Stacey Meily

Role: CONTACT

sas117@psu.edu

814-863-8622

Other Identifiers

MDP

Identifier Type: -

Identifier Source: org_study_id