The Metabolic Effects of Intermittent Fasting

Not Applicable

Recruiting

• Conditions: Normal and Overweight Individuals at High-risk of Diabetes
• Interventions: Behavioral: Fasting arm; Behavioral: Counseling; Behavioral: Weight maintenance

• Registration Number: NCT05722873
• Lead Sponsor: University of Pittsburgh

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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2023-01-27
• Study First Submitted QC: 2023-02-01
• Study First Posted: 2023-02-10
• Study Start: 2023-10-25
• Status Verified: 2025-05
• Last Update Submitted: 2025-05-08
• Last Update Posted: 2025-05-14
• Primary Completion: 2028-06-30
• Study Completion: 2028-06-30

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 90

Inclusion Criteria

1. Men and women, ages 25-45 years
2. BMI of at least 21 kg/m2 and up to and including BMI of 29 kg/m2
3. Normal thyroid function
4. Regular menses (women)
5. At least one first-degree relative with type 2 diabetes (T2D) and/or history of gestational diabetes

Exclusion Criteria

1. Any chronic diseases including hypertension and Type 2 diabetes mellitus
2. 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%)
3. Chronic medications, including oral contraceptive pills
4. Pregnant and/or breastfeeding
5. History of an eating disorder
6. 25-OH vitamin D level < 20 ng/mL
7. Active substance abuse, including alcohol
8. Subjects with a prior history of intermittent fasting
9. 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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Fasting with weight maintenance	Fasting arm	Subjects will fast one-day per week for 12 weeks and maintain body weight
Counseling	Counseling	Subjects will be counseled on optimal diet and activity recommendations to maintain/achieve a normal BMI (standard of care)
Fasting	Fasting arm	Subjects will fast one-day per week for 12 weeks
Fasting with weight maintenance	Weight maintenance	Subjects will fast one-day per week for 12 weeks and maintain body weight

Primary Outcome Measures

Name	Time	Method
Triglyceride carbon content and degree of saturation	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	Baseline, 3 months	Change in trabecular bone volume fraction at the radius between Baseline and Final Intervention visits

Secondary Outcome Measures

Name	Time	Method
Insulin sensitivity	Baseline, 3 months	Change in insulin sensitivity as assessed by hyperinsulinemic-euglycemic clamp between Baseline and Final Intervention visits

Trial Locations

Locations (1)

University of Pittsburgh; 🇺🇸 Pittsburgh, Pennsylvania, United States