NCT05722873 · University of Pittsburgh
The Metabolic Effects of Intermittent Fasting
What this study is about
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.
View original scientific description
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.
Interventions
BEHAVIORAL
Fasting arm
Study participants will fast one day per week for 12 weeks
BEHAVIORAL
Weight maintenance
Study participants will be counseled to maintain body weight
BEHAVIORAL
Counseling
Study participants will be counseled on optimal diet and activity recommendations for maintaining/achieving a normal BMI
Primary outcome measures
Triglyceride carbon content and degree of saturation
Time frame: Baseline, 3 months
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
Trabecular bone microarchitecture
Time frame: Baseline, 3 months
Change in trabecular bone volume fraction at the radius between Baseline and Final Intervention visits
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- 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
Exclusion criteria
- 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
- 25-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
Where
- Pittsburgh, Pennsylvania
Collaborators
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 18, 2026 · Source of record for eligibility and locations