Recruiting

Mediterranean Diet

Sponsor:

Penn State University

Code:

NCT07229781

Conditions

Prediabetes

Eligibility Criteria

Sex: All

Age: 25 - 65

Healthy Volunteers: Not accepted

Interventions

Mediterranean-style diet with potatoes

Traditional-style Mediterranean diet

Study Details

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.

Conditions

Prediabetes

Study ID

NCT07229781

Start date

Aug 26, 2026

Status verified date

Oct, 2026

Completion date

Apr 30, 2028

Anticipated

Primary completion date

Apr 30, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 25 - 65

Healthy Volunteers: Not accepted

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

Study Design

Enrollment

74 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Prevention

Interventions and Outcome Measures

Arms

experimental: Mediterranean-style diet with potato (MED-P)

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

active comparator: 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.

Interventions

Mediterranean-style diet with potatoes

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

Traditional-style Mediterranean diet

Traditional-style Mediterranean diet higher in grains

Primary outcome measure

  • Change in HbA1c [ Time Frame: 12-weeks ]

Central Contacts and Locations

Central contacts

Kristina Petersen, PhD

814-865-7206kup63@psu.edu

Stacey Meily

814-863-8622sas117@psu.edu

Locations

The Pennsylvania State University

Recruiting

University Park, Pennsylvania, United States, 16802

Contacts

Kristina Petersen, PhD

814-865-7206kup63@psu.edu

More Information

Sponsor

Penn State University

Last update posted

Oct 5, 2026

Last verified

Oct, 2026

Keywords

  • prediabetes
  • diet
  • nutrition
  • Mediterranean diet
  • cardiovascular disease

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-06. This information was provided to ClinicalTrials.gov by Penn State University on 2026-10-05. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.