The Metabolic Effects of Intermittent Fasting

NCT05722873 | Recruiting DMC

• 2 other identifiers: STUDY21120112R01DK133578
• Study Type: interventional
• Target: 90
• Locations: 1 country
• Sites: 1

Brief Summary

Caloric restriction has beneficial metabolic effects in humans including weight loss and improvement in blood pressure and lipid levels. Intermittent fasting has emerged as a popular alternative to caloric restriction as it does not require daily adherence to a dietary protocol, but whether the benefits of fasting protocols are dependent on weight loss is not known. In this study, the investigators will explore the metabolic effects of fasting and evaluate whether these effects, including negative effects on bone metabolism, are independent of weight loss.

Conditions

Normal and Overweight Individuals at High-risk of Diabetes

Outcome Measures

Primary Outcomes (2)

• Triglyceride carbon content and degree of saturation

  Change in triglyceride carbon content and degree of saturation (% variation explained by both carbon number and double bond number in a regression model) between Baseline and Final Intervention visits

  Baseline, 3 months

• Trabecular bone microarchitecture

  Change in trabecular bone volume fraction at the radius between Baseline and Final Intervention visits

  Baseline, 3 months

Secondary Outcomes (1)

• Insulin sensitivity

  Baseline, 3 months

Study Arms (3)

Fasting

EXPERIMENTAL

Subjects will fast one-day per week for 12 weeks

Behavioral: Fasting arm

Fasting with weight maintenance

EXPERIMENTAL

Subjects will fast one-day per week for 12 weeks and maintain body weight

Behavioral: Fasting arm; Behavioral: Weight maintenance

Counseling

PLACEBO COMPARATOR

Subjects will be counseled on optimal diet and activity recommendations to maintain/achieve a normal BMI (standard of care)

Behavioral: Counseling

Interventions

Fasting arm BEHAVIORAL

Study participants will fast one day per week for 12 weeks

Fasting; Fasting with weight maintenance

Weight maintenance BEHAVIORAL

Study participants will be counseled to maintain body weight

Fasting with weight maintenance

Counseling BEHAVIORAL

Study participants will be counseled on optimal diet and activity recommendations for maintaining/achieving a normal BMI

Counseling

Eligibility Criteria

• Age: 21 Years - 45 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Men and women, ages 21-45 years
• BMI of at least 21 kg/m2 and up to and including BMI of 29 kg/m2
• Normal thyroid function
• Regular menses (women)
• At least one first-degree relative with type 2 diabetes (T2D) and/or history of gestational diabetes

You may not qualify if:

• Any chronic diseases including hypertension and Type 2 diabetes mellitus
• Indication for lipid-lowering therapy in non-diabetics, using the more stringent AHA guideline cutoff (LDL\>190 or an estimated 10-year ASCVD risk of \>7.5%)
• Chronic medications, including oral contraceptive pills
• Pregnant and/or breastfeeding
• History of an eating disorder
• OH vitamin D level \< 20 ng/mL
• Active substance abuse, including alcohol
• Subjects with a prior history of intermittent fasting
• The study physician feels that the subject may not be able to safely complete the protocol or may place themselves at risk by undergoing the protocol

Sponsors & Collaborators

• University of Pittsburgh: lead
• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): collaborator

Study Sites (1)

University of Pittsburgh

Pittsburgh, Pennsylvania, 15213, United States

RECRUITING

Related Publications (1)

• Quaytman JA, David NL, Venugopal S, Amorim T, Beatrice B, Toledo FGS, Miller RG, Steinhauser ML, Fazeli PK. Intermittent fasting for systemic triglyceride metabolic reprogramming (IFAST): Design and methods of a prospective, randomized, controlled trial. Contemp Clin Trials. 2024 Nov;146:107698. doi: 10.1016/j.cct.2024.107698. Epub 2024 Sep 17.

  PMID: 39299543 DERIVED

MeSH Terms

Interventions

Body Weight Maintenance; Counseling

Intervention Hierarchy (Ancestors)

Body Weight; Body Size; Growth; Growth and Development; Physiological Phenomena; Mental Health Services; Behavioral Disciplines and Activities; Community Health Services; Health Services; Health Care Facilities Workforce and Services

Study Officials

• Pouneh Fazeli, MD

  University of Pittsburgh

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Pouneh Fazeli, MD

CONTACT

412-648-9770; pkfazeli@pitt.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor of Medicine

Model Details: Randomized, controlled study

Study Record Dates

• First Submitted: January 27, 2023
• First Posted: February 10, 2023
• Study Start: October 25, 2023
• Primary Completion (Estimated): June 30, 2028
• Study Completion (Estimated): June 30, 2028
• Last Updated: August 7, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ICF
• Time Frame: Beginning 12 months after publication. No end date.
• Access Criteria: Researchers who wish to access deidentified data.

Locations

US (1)