Time Restricted Feeding (4-hour Versus 6-hour) for Weight Loss in Obese Adults

The aims of this proposal are to compare the effects of 4-h versus 6-h time restricted feeding (TRF) on body weight and metabolic disease risk factors in adults with obesity. To test the study objectives, a 10-week randomized, controlled, parallel-arm trial, divided into 2 consecutive periods: (1) 2-week baseline period; and (2) 8-week TRF weight loss period, will be implemented. Obese subjects will be randomized to 1 of 3 groups: (1) 4-h TRF, (2) 6-h TRF, or a no-intervention control group. This study will be the first randomized controlled trial to compare 4-h versus 6-h TRF.

Study Overview

• Status: Completed
• Conditions: Obesity; Diabetes
• Intervention / Treatment: Behavioral: Time restricted feeding

Detailed Description

Modest weight loss of 5-10% is sufficient to reduce metabolic disease risk in obese individuals. The first line of therapy prescribed for weight loss is daily calorie restriction (CR; 25% restriction every day). However, adherence to CR greatly diminishes after 4-6 weeks, due to subject frustration with constantly having to count calories and never being able to eat freely. In light of these issues with CR, another approach that limits timing of food intake, instead of number of calories consumed, has been developed. This strategy is termed time restricted feeding (TRF), and involves confining the period of food intake to 8 h/d (10 am to 6 pm) without calorie counting. Preliminary findings of 8-h TRF demonstrate modest weight loss and blood pressure reductions after 12 weeks. What remains unknown however, is whether shorter feeding windows during TRF (such as 4-h or 6-h feeding windows) can produce even greater weight loss in obese adults. Also of interest, is the impact of these shorter feeding windows on metabolic disease risk indicators (such as plasma lipids, blood pressure, and insulin resistance, inflammation and oxidative stress). Accordingly, the aims of this proposal are: AIM 1: To compare the effects of 4-h versus 6-h time restricted feeding (TRF) on body weight in adults with obesity; AIM 2: To compare the effects of 4-h versus 6-h TRF on metabolic disease risk factors in adults with obesity. To test the study objectives, a 10-week randomized, controlled, parallel-arm trial, divided into 2 consecutive periods: (1) 2-week baseline period; and (2) 8-week TRF weight loss period, will be implemented. Obese subjects will be randomized to 1 of 3 groups: (1) 4-h TRF, (2) 6-h TRF, or a no-intervention control group. This study will be the first randomized controlled trial to compare 4-h versus 6-h TRF on body weight and metabolic disease risk markers.

• Study Type: Interventional
• Enrollment (Actual): 82
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Illinois
    • Chicago, Illinois, United States, 60612
      • University of Illinois Chicago

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Male or female;
• body mass index (BMI) between 30.0 and 49.9 kg/m2;
• age between 18 and 65 years; sedentary (light exercise less than 1 h per week) or moderately active (moderate exercise 1 to 2 h per week);
• weight stable for >3 months prior to the beginning of the study (gain or loss <4 kg);
• able to give written informed consent

Exclusion Criteria:

• Smoker; diabetic;
• taking weight loss medications;
• taking medication that requires eating food before (or with) the medication; history of eating disorders;
• night-shift workers;
• perimenopausal;
• pregnant women

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 4-hour Time restricted feeding; 4-h TRF subjects will consume food ad libitum between 3pm and 7pm (4-h feeding window), and refrain from eating and drinking caloric beverages from 7pm to 3pm (20-h fasting window) each day. These subjects will not be instructed to limit/monitor energy intake during the feeding window. Subjects will be encouraged to drink plenty of water during the fasting period.	Behavioral: Time restricted feeding; TRF subjects will consume food ad libitum during the feeding window (4-h or 6-h window), and refrain from eating during the fasting window (20-h or 18-h window)
No Intervention: Control; Controls will be instructed to maintain their weight throughout the trial, and not to change eating or physical activity habits. Controls will visit the research center at the same frequency as the TRF groups (for outcome measurements).
Experimental: 6-hour Time restricted feeding; 6-h TRF subjects will consume food ad libitum between 1pm and 7pm (6-h feeding window), and refrain from eating and drinking caloric beverages from 7pm to 1pm (18-h fasting window) each day. These subjects will not be instructed to limit/monitor energy intake during the feeding window. Subjects will be encouraged to drink plenty of water during the fasting period.	Behavioral: Time restricted feeding; TRF subjects will consume food ad libitum during the feeding window (4-h or 6-h window), and refrain from eating during the fasting window (20-h or 18-h window)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline to week 8 in body weight	Measured by an electronic scale	Measured at week 1 and 8

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline to week 8 in body composition	Measured by DXA	Measured at week 1 and 8
Change from baseline to week 8 in Insulin resistance	Measured as HOMA-IR	Measured at week 1 and 8
Change from baseline to week 8 in Fasting glucose	Measured with a hexokinase reagent kit	Measured at week 1 and 8
Change from baseline to week 8 in Fasting insulin	Measured as total immunoreactive insulin	Measured at week 1 and 8
Change from baseline to week 8 in Blood pressure	Measured by a blood pressure cuff	Measured at week 1 and 8
Change from baseline to week 8 in adverse events	Measured by questionnaire	Measured weekly from baseline to week 8
Change from baseline to week 8 in plasma lipids	Measured by outside lab (Medstart, IN)	Measured at week 1 and 8
Change from baseline to week 8 in heart rate	Measured by a blood pressure cuff	Measured at week 1 and 8
Change from baseline to week 8 in inflammatory markers (TNF-a, IL-6)	Measured by ELISA	Measured at week 1 and 8
Change from baseline to week 8 in oxidative stress (8-isoprostane)	Measured by ELISA	Measured at week 1 and 8
Change from baseline to week 8 in calorie and macronutrient intake	Measured by food record	Measured at week 1 and 8
Change from baseline to week 8 in physical activity (steps/d)	Measured by activity monitor	Measured at week 1 and 8
Change from baseline to week 8 in diet adherence	Measured by a questionnaire	Measured weekly from baseline to week 8
Change from baseline to week 8 in sleep quality	Measured by a questionnaire	Measured at week 1 and 8
Change from baseline to week 8 in insomnia severity	Measured by a questionnaire	Measured at week 1 and 8
Change from baseline to week 8 in risk of sleep apnea	Measured by a questionnaire	Measured at week 1 and 8
Change from baseline to week 8 in sex steroid levels (estrogen, androgens, sex hormone binding globulin)	Measured by a ELISA	Measured at week 1 and 8

Collaborators and Investigators

• Sponsor: University of Illinois at Chicago

Publications and helpful links

General Publications

• Cienfuegos S, Gabel K, Kalam F, Ezpeleta M, Lin S, Varady KA. Changes in body weight and metabolic risk during time restricted feeding in premenopausal versus postmenopausal women. Exp Gerontol. 2021 Oct 15;154:111545. doi: 10.1016/j.exger.2021.111545. Epub 2021 Aug 31.
• Cienfuegos S, Gabel K, Kalam F, Ezpeleta M, Wiseman E, Pavlou V, Lin S, Oliveira ML, Varady KA. Effects of 4- and 6-h Time-Restricted Feeding on Weight and Cardiometabolic Health: A Randomized Controlled Trial in Adults with Obesity. Cell Metab. 2020 Sep 1;32(3):366-378.e3. doi: 10.1016/j.cmet.2020.06.018. Epub 2020 Jul 15.

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2019
• Primary Completion (Actual): October 30, 2019
• Study Completion (Actual): October 30, 2019

Study Registration Dates

• First Submitted: March 4, 2019
• First Submitted That Met QC Criteria: March 7, 2019
• First Posted (Actual): March 8, 2019

Study Record Updates

• Last Update Posted (Actual): June 24, 2022
• Last Update Submitted That Met QC Criteria: June 19, 2022
• Last Verified: June 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Body Weight; Body Weight Changes; Weight Loss
• Other Study ID Numbers: 2018-1525

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No