NCT07430852

Brief Summary

The goal of this research is to investigate genetic and environmental factors that contribute to obesity through brain inflammation. The main questions are 1) if identical twins, who differ in food consumption habits, have differences in adiposity markers and brain inflammation and 2) if signs of brain inflammation in response to a specific diet is modified by genetics.

Trial Health

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Trial Health Score

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

Enrollment
110

participants targeted

Target at P50-P75 for not_applicable

Timeline
45mo left

Started Sep 2026

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

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

First Submitted

Initial submission to the registry

February 18, 2026

Completed
6 days until next milestone

First Posted

Study publicly available on registry

February 24, 2026

Completed
6 months until next milestone

Study Start

First participant enrolled

September 1, 2026

Expected
3.2 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

November 1, 2029

6 months until next milestone

Study Completion

Last participant's last visit for all outcomes

April 30, 2030

Last Updated

February 24, 2026

Status Verified

February 1, 2026

Enrollment Period

3.2 years

First QC Date

February 18, 2026

Last Update Submit

February 18, 2026

Conditions

GeneticsObesity

Keywords

GliosisEating patterns

Outcome Measures

Primary Outcomes (2)

  • Study 1: Hypothalamic Gliosis

    T2 relaxation time as measured by brain MRI

    at enrollment

  • Study 2: Hypothalamic Gliosis

    T2 relaxation time as measured by brain MRI

    7 days of diet intervention

Study Arms (2)

Study 1, A co-twin control study of habitual diet

NO INTERVENTION

Monozygotic twin pairs with differential habitual diet practices will undergo measurements including body composition, and MRI measures of hepatic adiposity and neuroinflammation.

Study 2, A twin study of controlled diet

EXPERIMENTAL

Monozygotic twin pairs will be provided an assigned diet for 14-days.

Behavioral: Diet modification

Interventions

Diet modificationBEHAVIORAL

Participants will be provided all meals for a 14-day period. For 7 of the days, meals will be 150% of estimated daily caloric needs and for the other 7 days, meals will be low in calories, consistent with recommendations for weight loss.

Study 2, A twin study of controlled diet

Eligibility Criteria

Age20 Years - 45 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Age 20-45 years
  • Differs in habitual diet from co-twin (study 1).
  • Willing to undergo 7-day overfeeding and hypocaloric feeding periods (study 2)
  • Member of the Washington State Twin Registry

You may not qualify if:

  • History of bariatric surgery or active participation in weight-loss program
  • Major medical or neurological disorder (e.g., diabetes, multiple sclerosis)
  • Known gallbladder disease, anemia, impaired thyroid, kidney or liver function or hypertriglyceridemia (\>350 mg/dl) (study 2)
  • Current use of weight-loss medications or other medications known to alter appetite (e.g., atypical anti-psychotics)
  • High levels of vigorous physical activity (\>300 min./week)
  • Pregnancy, menopause, or breastfeeding
  • Individuals with severe food allergies and dietary restrictions (e.g., vegan/vegetarian, gluten-free, others) (study 2)
  • Co-twin unwilling or unable to participate
  • MRI contraindication (e.g., implanted metal, claustrophobia)
  • Lifetime eating disorder
  • Current smoking or heavy alcohol use (≥ 2 drinks per day for females and ≥ 3 drinks per day for males)
  • BMI \> 45 kg/m2 (study 1)
  • BMI \> 35 kg/m2 (study 2)
  • Weight \> 350 pounds or determined to be safe by MRI tech (MRI limit)
  • Inability to participate in a controlled diet program (study 2) or undergo other study procedures
  • +1 more criteria

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of Washington

Seattle, Washington, 98109, United States

Location

MeSH Terms

Conditions

ObesityGliosis

Interventions

Diet Therapy

Condition Hierarchy (Ancestors)

OverweightOvernutritionNutrition DisordersNutritional and Metabolic DiseasesBody WeightSigns and SymptomsPathological Conditions, Signs and SymptomsPathologic Processes

Intervention Hierarchy (Ancestors)

Nutrition TherapyTherapeutics

Study Officials

  • Ellen Schur, MD, MS

    University of Washington

    PRINCIPAL INVESTIGATOR

Central Study Contacts

INTERACT Study

CONTACT

206-616-6360interactstudy@uw.edu

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NON RANDOMIZED
Masking
NONE
Purpose
BASIC SCIENCE
Intervention Model
SINGLE GROUP
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Professor: School of Medicine

Study Record Dates

First Submitted

February 18, 2026

First Posted

February 24, 2026

Study Start (Estimated)

September 1, 2026

Primary Completion (Estimated)

November 1, 2029

Study Completion (Estimated)

April 30, 2030

Last Updated

February 24, 2026

Record last verified: 2026-02

Data Sharing

IPD Sharing
Will not share

Locations

US(1)