Isocaloric Dietary Restriction vs. Bariatric Surgery for Obesity Treatment

Study Overview
=================
Brief Summary
-----------------
This is a prospective, randomized, two-armed study to assess the efficacy and safety of isocaloric dietary restriction in the treatment of obese without diabetic for a period of 3 months. Then, participants would be given dietary guidance and health education and followed up for 1 year.

Detailed Description
-----------------
This is a randomized, open-label, two arms trial. Based on inclusion and exclusion criteria, 72 eligible patients, who are 18-45 years old, with BMI between 35 to 45kg/m2 are assigned to one of two intervention groups: isocaloric dietary restriction; bariatric surgery. Both groups were given a dietary intervention for a period of 3 months (about 1 month rigorous supervision confined in inpatient department, followed with 2 months self-management in outpatient department). The main purpose of this study is to clarify the efficacy of isocaloric dietary restriction, compared to bariatric surgery, in losing weight and improving metabolic factors. This is an investigator-initiated study performed by department of endocrinology and metabolic disease, Ruijin hospital affiliated with Shanghai Jiaotong University School of Medicine.

Official Title
-----------------
Isocaloric Dietary Restriction vs. Bariatric Surgery for Obesity Treatment

Conditions
-----------------
Obesity

Intervention / Treatment
-----------------
* Dietary Supplement: isocaloric dietary restriction
* Procedure: Bariatric surgery


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Age between 18 to 45 years old 35 ≤ BMI ≤ 45 kg/m2 Exclusion Criteria: Obesity induced by other endocrinologic disorders Severe gastrointestinal diseases or contraindication for surgery History or newly known of diabetes Use of hypoglycemic medications, antibiotic in the preceding 2 months, or yogurt within 5 days Weight change more than 5% of body weight within the past 3 months Severe or unstable cardiovascular, liver or renal diseases or known cancer History of drug or alcohol abuse or other substance abuse Any mental disorders or current use of antidepressantsPregnancy or lactation or consideration of pregnancy Allergies to specific food ingredients in the intervention

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: isocaloric dietary restriction<br>Very low caloric diet 400 kcal/d for a week, 600 kcal/d for another week and 800 kcal/d for 2 weeks and 1000 kcal/d for 2 months. | Dietary Supplement: isocaloric dietary restriction<br>* Very low caloric diet<br>|
| Active Comparator: Bariatric surgery<br>Laparoscopic vertical sleeve gastrectomy | Dietary Supplement: isocaloric dietary restriction<br>* Very low caloric diet<br>Procedure: Bariatric surgery<br>* Laparoscopic vertical sleeve gastrectomy<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Body weight | Change of body weight | 1,3,6,12 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Body fat mass | Body fat mass will be measured by DEXA. | 1,3,6,12 month | 
| Body fat free mass | Body fat free mass will be measured by DEXA. | 1,3,6,12 month | 
| Abdominal fat | Abdominal fat will be measured using Magnetic Resonance Imaging. | 1,3,6,12 month | 
| Resting energy expenditure | Resting energy expenditure will be measured by metabolic chamber. | 1,3,6,12 month | 
| Total energy expenditure | Total energy expenditure will be measured by metabolic chamber. | 1,3,6,12 month | 
| Glucose | Glucose will be measured using an automatic biochemical analyzer. | 1,3,6,12 month | 
| LDL-C | LDL-C will be measured using an automatic biochemical analyzer. | 1,3,6,12 month | 
| Blood pressure | Both systolic pressure and diastolic pressure will be measured using electronic blood pressure monitor. | 1,3,6,12 month |