Intermittent Eating on Sustaining Weight-loss in Obesity (INTEREST)

Effects of Intermitting Eating on Weight-Loss Maintenance and Cardiometabolic Risk Factors in Obese Adults: A Randomized Clinical Trial

Weight regain after weight loss is a major problem in the treatment of obesity. Two novel types of intermittent fasting recently have received more attention: the 5:2 diet and time-restricted eating (TRE). TRE requires individuals to eat in a specified number of hours per day (typically 4 to 10 hours) without energy intake restriction. The 5:2 diet involves 5 feast days and 2 fast days per week; participants eat ad libitum without restriction on feast days while 25% of energy needs (approximately 500-800 kcal per day) are consumed on fast day. This randomized controlled trial aimed to evaluate the effect of TRE and the 5:2 diet on weight loss maintenance and cardiometabolic risk factors after a low-calorie diet in obese adults over 12 months compared to usual health care.

Study Overview

• Status: Recruiting
• Conditions: Obesity
• Intervention / Treatment: Behavioral: Time-restricted eating; Behavioral: The 5:2 diet

Detailed Description

Weight regain after weight loss is a major problem in the treatment of persons with obesity. Two novel types of intermittent fasting recently have received more attention: the 5:2 diet and time-restricted eating (TRE). TRE requires individuals to eat in a specified number of hours per day (typically 4 to 10 hours) without energy intake restriction. The 5:2 diet involves 5 feast days and 2 fast days per week; participants eat ad libitum without restriction on feast days while 25% of energy needs (approximately 500-800 kcal per day) are consumed on fast day. Preliminary evidence suggests that both TRE and the 5:2 diet have beneficial effects on weight loss and cardioprotection in humans. Whether TRE or the 5:2 diet is an effective approach for weight-loss maintenance remains unknown. This randomized controlled trial aimed to evaluate the effect of TRE and the 5:2 diet on weight loss maintenance and cardiometabolic risk factors after a low-calorie diet in obese adults over 12 months compared to usual health care. All participants who have achieved greater than 5% of weight loss after a 8-week low-calorie-diet induced weight loss phase, will be assigned to one of the three study groups (TRE, the 5:2 diet and control groups) in a 1:1:1 ratio. Participants in the TRE group will be instructed to eat during a window of 8 h/d (8 am to 4 pm) over 12 months. Participants in the 5:2 diet group will be instructed to consume 500-600 kcal/d on fast days and eat ad libitum on feast days. Participants in the control group were instructed to receive usual health care.

• Study Type: Interventional
• Enrollment (Estimated): 270
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Huijie Zhang, MD. PhD.; Phone Number: +86-020-61641635; Email: huijiezhang2005@126.com

Study Locations

• China
  • Guangdong
    • Guangzhou, Guangdong, China, 510515
      • Recruiting
      • Nanfang Hospital, Southern Medical University
      • Contact: Huijie Zhang, MD. PhD.; Phone Number: +86-020-61641635; Email: huijiezhang2005@126.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 1.Man or women aged 18-75 years;
• 2.Body mass index (BMI)of 28.0 to 45.0 kg/m2;

Exclusion Criteria:

• 1. History of HIV, hepatitis B or C (self-report) or active pulmonary tuberculosis;
• 2. Diagnosis of type 1 and type 2 diabetes;
• 3. History of malignant tumors;
• 4. Serious liver dysfunction or chronic kidney disease (AST or ALT > 3 times the upper limit of normal, or eGFR<30 ml/min/1.73 m2);
• 5. History of serious cardiovascular or cerebrovascular disease (angina, myocardial infarction or stroke) in the past 6 months;
• 6. History of severe gastrointestinal diseases or gastrointestinal surgery in the past 12 months;
• 7. History of Cushing's syndrome, hypothyroidism, acromegaly, hypothalamic obesity;
• 8. Being a smoker or having been a smoker in the 3 months prior to their screening visit;
• 9. Taking medications affecting weight or energy intake/energy expenditure in the last 6 months, including weight loss medications, antipsychotic drugs or other medications as determined by the study physician;
• 10. Currently participating in weight loss programs or weight change in the past 3 months (> 5% current body weight) ;
• 11. Women who are pregnant or plan to become pregnant;
• 12. Patients who cannot be followed for 24 months (due to a health situation or migration);
• 13. Patients who are unwilling or unable to give informed consent.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: The TRE group; Participants in the TRE group will be instructed to eat during a window of 8 h/d (8 am to 4 pm).	Behavioral: Time-restricted eating; Participants in the TRE group will be instructed to eat during a window of 8 h/d (8 am to 4 pm)
Experimental: The 5:2 diet group; Participants in the 5:2 diet group will be instructed to consume 500-600 kcal/d on fast days and eat ad libitum on feast days.	Behavioral: The 5:2 diet; Participants will be instructed to consume 500-600 kcal/d on fast days and eat ad libitum on feast days.
No Intervention: Control; Participants in the control group will receive a general lifestyle counseling.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change in body weight over 12 months	Baseline to months 12

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in body fat composition meassured by DEXA	Body composition is meassured by dual-energy X-ray absorptiometry scans	Baseline to months 12
Change in waist circumference		Baseline to months 12
Change in body mass index		Baseline to months 12
Change in liver fat	Liver fat is assessed by liver Fibroscan.	Baseline to months 12
Change in systolic blood pressure		Baseline to months 12
Change in diastolic blood pressure		Baseline to months 12
Change in serum triglycerides		Baseline to months 12
Change in serum total cholesterol		Baseline to months 12
Change in serum LDL-c		Baseline to months 12
Change in HbA1c		Baseline to months 12
Change in insulin sensitivity	Insulin sensitivity is assessed by HOMA-IR	Baseline to months 12
Change in β cell function	β cell function is assessed by HOMA-B	Baseline to months 12
Change in arterial stiffness measured by pulse wave velocity	arterial stiffness is measured by pulse wave velocity (PWV)	Baseline to months 12
Change in depression score measured by the Patient Health Questionnaire-9	Depression is measured by the Patient Health Questionnaire-9 (PHQ-9)	Baseline to months 12
Change in quality of sleep score measured by the Pittsburgh sleep quality index	Quality of sleep is measured by the Pittsburgh sleep quality index (PSQI)	Baseline to months 12
Change in quality of life score measured by the 12-item Short-Form Health Survey Questionnaire	Quality of life is measured by the 12-item Short-Form Health Survey Questionnaire (SF-12)	Baseline to months 12

Collaborators and Investigators

• Sponsor: Nanfang Hospital, Southern Medical University
• Investigators: Principal Investigator: Huijie Zhang, MD. PhD., Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2022
• Primary Completion (Estimated): July 15, 2025
• Study Completion (Estimated): July 15, 2025

Study Registration Dates

• First Submitted: June 18, 2022
• First Submitted That Met QC Criteria: July 6, 2022
• First Posted (Actual): July 12, 2022

Study Record Updates

• Last Update Posted (Estimated): November 9, 2023
• Last Update Submitted That Met QC Criteria: November 8, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Keywords: Obesity; Time restricted eating; The 5:2 diet; Weight loss maintenance
• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Overweight; Body Weight; Body Weight Changes; Obesity; Weight Loss
• Other Study ID Numbers: NFEC-2022-155

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