NCT07229781

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.

Trial Health

65
Monitor

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
74

participants targeted

Target at P50-P75 for not_applicable

Timeline
23mo left

Started Jun 2026

Typical duration for not_applicable

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress2%
Jun 2026Apr 2028

First Submitted

Initial submission to the registry

November 13, 2025

Completed
4 days until next milestone

First Posted

Study publicly available on registry

November 17, 2025

Completed
7 months until next milestone

Study Start

First participant enrolled

June 1, 2026

Completed
1.9 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

April 30, 2028

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

April 30, 2028

Last Updated

April 2, 2026

Status Verified

April 1, 2026

Enrollment Period

1.9 years

First QC Date

November 13, 2025

Last Update Submit

April 1, 2026

Conditions

Prediabetes

Keywords

prediabetesdietnutritionMediterranean dietcardiovascular disease

Outcome Measures

Primary Outcomes (1)

  • Change in HbA1c

    HbA1c will be assessed at baseline and 12-weeks and expressed as percentage . The change in HbA1c will be calculated by subtracting the baseline value from the 12 week value and expressed as percentage point change.

    12-weeks

Secondary Outcomes (18)

  • Change in fasting glucose

    12-weeks

  • Change in mean glucose

    12-weeks

  • Change in mean time in range

    12-weeks

  • Change in glycemic variability

    12-weeks

  • Change in fasting insulin

    12-weeks

  • +13 more secondary outcomes

Study Arms (2)

Mediterranean-style diet with potato (MED-P)

EXPERIMENTAL

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

Other: Mediterranean-style diet with potatoes

Traditional-style Mediterranean dietary pattern (MED)

ACTIVE COMPARATOR

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

Other: Traditional-style Mediterranean diet

Interventions

Mediterranean-style diet with potatoesOTHER

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

Mediterranean-style diet with potato (MED-P)
Traditional-style Mediterranean dietOTHER

Traditional-style Mediterranean diet higher in grains

Traditional-style Mediterranean dietary pattern (MED)

Eligibility Criteria

Age25 Years - 65 Years
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • 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

You may not qualify if:

  • 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
  • +11 more criteria

Contact the study team to confirm eligibility.

Sponsors & Collaborators

MeSH Terms

Conditions

Prediabetic StateCardiovascular Diseases

Condition Hierarchy (Ancestors)

Diabetes MellitusGlucose Metabolism DisordersMetabolic DiseasesNutritional and Metabolic DiseasesEndocrine System Diseases

Central Study Contacts

Kristina Petersen, PhD

CONTACT

814-865-7206kup63@psu.edu

Stacey Meily

CONTACT

814-863-8622sas117@psu.edu

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
OUTCOMES ASSESSOR
Purpose
PREVENTION
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Associate Professor

Study Record Dates

First Submitted

November 13, 2025

First Posted

November 17, 2025

Study Start

June 1, 2026

Primary Completion (Estimated)

April 30, 2028

Study Completion (Estimated)

April 30, 2028

Last Updated

April 2, 2026

Record last verified: 2026-04

Data Sharing

IPD Sharing
Will share
Shared Documents
STUDY PROTOCOL, SAP
Time Frame
The SAP and protocol will be posted on clinicaltrials.gov prior to enrollment commencing.