Prolonged Daily Fasting for Obesity

Recruiting in Palo Alto (17 mi)

Age: 18+

Sex: Any

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Academic

Waitlist Available

Sponsor: University of Minnesota

No Placebo Group

Trial Summary

What is the purpose of this trial?Purpose: Obesity is reaching epidemic proportions, affecting 36% of the adult population in the United States. There is intense interest in dietary management to treat obesity and its associated complications. The first line of obesity treatment is caloric restriction (CR), although recidivism is common. For moderate CR, attrition rates of 20% are often reported, therefore weight loss options beyond CR are urgently needed.

Eligibility Criteria

This trial is for adults with obesity (BMI between 30 and 55) who have had a stable weight for the past three months, use a smartphone, wake up early, get average sleep, and have an eating window of over 14 hours. It's not for shift workers, pregnant individuals, those with certain medical conditions or abnormal lab results, history of eating disorders or using specific medications.

Inclusion Criteria

Own a smartphone compatible with the myCircadianClock (mCC) phone application

Eating window (time between 1st food intake and last food take) ≥14 hours using mCC

Self-reported habitual wakening between 5-9 am

+5 more

Exclusion Criteria

Concern for active eating disorder per screening questionnaire

Illiteracy

MRI contraindication (metal in body, claustrophobia)

+8 more

Participant Groups

The study is testing if prolonged daily fasting can be as effective as traditional calorie cutting in helping obese people manage their weight. Participants will either follow Time Restricted Eating (TRE) where they eat during limited hours or Caloric Restriction (CR), reducing overall food intake.

3Treatment groups

Experimental Treatment

Active Control

Group I: Time Restricted Eating (TRE)Experimental Treatment1 Intervention

For the TRE group, we will restrict the eating window to 8 hours, where they will eat ad libitum. This is the same interval established by Dr. Panda and by our preliminary data. This interval will be entered into the mCC app and participants will be asked to adhere to this eating window during the intervention. All eating occasions will be logged using the mCC app. Only water and medications will be allowed outside of the eating window.

Group II: Caloric Restriction (CR)Active Control1 Intervention

Participants randomized to CR will meet with the study dietitian prior to the intervention and be counseled on options to reduce their caloric intake by 15%, while maintaining their eating window. The 15% reduction was selected as our preliminary data and recent literature suggest that TRE with ad libitum intake reduces caloric intake by \~270 to 300 cal/day. The 15% CR is similar to the 11.9% CR achieved by the CALERIE-2 study, which is a 2 year study of CR.26 All eating occasions will be logged using the mCC app. The weekly dietitian review of the mCC information will include maintenance of the eating window and examination of dietary intake to determine compliance with the 15% CR.

Group III: Unrestricted Eating (non-TRE)Active Control1 Intervention

For the unrestricted eating (non-TRE) group, participants will eat ad libitum per their usual habits. They will receive initial counseling about mCC logging. All eating occasions will be logged using the mCC app.