Intermittent Eating on Sustaining Weight-loss in Obesity

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

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

Conditions
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Obesity

Intervention / Treatment
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* Behavioral: Time-restricted eating
* Behavioral: The 5:2 diet


Participation Criteria
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Eligibility Criteria
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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.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

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

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | 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 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Obesity, Time restricted eating, The 5:2 diet, Weight loss maintenance