Clinical trial NCT06963437: Interventions for Weight Regain After Bariatric Surgery
Official title: Comparison of Revisional Surgery, Ketogenic Diet, and Intermittent Fasting in Bariatric Surgery Patients With Weight Regain: A Prospective Randomized Controlled Study
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Obese Patients With Bariatric Surgery
Obese Patients (BMI ≥ 30 kg/m²)
Weight Regain Post Bariatric Surgery
Revisional Bariatric Surgery
Ketogenic Dieting
Intermittent Fasting
Keywords: weight regain post bariatric surgery
revisional bariatric surgery
ketogenic dieting
intermittent fasting
nutritional status
Lead sponsor: Medipol University
Sponsor class: OTHER
First posted: 2025-05-09
Enrollment: 56
Sex: ALL
Minimum age (years): 18
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: This study will be conducted on 56 patients who have experienced insufficient weight loss (IWL) or weight regain (WR) following bariatric surgery. Participants will be randomly assigned to one of four groups (n=14 per group):

RBS Group - patients undergoing revisional bariatric surgery (RBS)

VLCKD Group - patients following a very low-calorie ketogenic diet (VLCKD)

IF Group - patients following an intermittent fasting (IF) diet

Control Group - patients receiving standard post-bariatric nutritional follow-up as recommended by the ASMBS
Primary purpose: TREATMENT

Brief summary: Study Objective:

The aim of this study is to evaluate the effects of revisional bariatric surgery (RBS), very low-calorie ketogenic diet (VLCKD), and intermittent fasting (IF) on nutritional habits and clinical outcomes (anthropometric and biochemical measurements) in patients with insufficient weight loss (IWL) or weight regain (WR) after bariatric surgery, and to compare these findings with those of a control group.

Detailed description: Study Hypotheses:

1. In patients with IWL or WR after bariatric surgery, a diet following the bariatric care guidelines (BCGs) after revisional bariatric surgery (RBS) improves nutritional habits, anthropometric, and biochemical parameters.
2. In patients with IWL or WR after bariatric surgery, VLCKD improves nutritional habits, anthropometric, and biochemical parameters.
3. In patients with IWL or WR after bariatric surgery, IF regimen improves nutritional habits, anthropometric, and biochemical parameters.
4. In patients with IWL or WR after bariatric surgery, the diet program recommended by the ASMBS as part of standard post-bariatric care improves nutritional habits, anthropometric measurements, and biochemical parameters.

Eligibility criteria: Inclusion Criteria:

* Patients aged between 18 and 45 years who have undergone bariatric surgery (BS).
* Experiencing inadequate weight loss (IWL) within 18 months after surgery or weight regain (WR) following successful weight loss.
* Definitions used in the study:

IWL is defined as \<50% excess weight loss (EWL) 18 months postoperatively. WR is defined as \>25% regain of the lost weight (from the lowest achieved weight).

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Exclusion Criteria:

* Pregnant or lactating women.
* Patients with acute illnesses, infections, or comorbidities that may affect treatment efficacy or safety (e.g., cancer, type 1 diabetes, renal or hepatic failure, recent stroke or myocardial infarction, nephrolithiasis, substance or alcohol abuse, eating disorders, severe depression or other psychiatric disorders, inflammatory bowel disease, neoplasms, arrhythmic heart diseases, heart failure, respiratory failure).
* Patients currently receiving corticosteroid therapy.
* Professional athletes.

Primary outcomes:
measure: Change in Body Weight (kg)
timeFrame: Baseline and Week 6
measure: Change in Body Mass Index (kg/m²)
timeFrame: Baseline and Week 6
measure: Change in Waist Circumference (cm)
timeFrame: Baseline and Week 6
measure: Change in Body Composition (Fat Mass %, Muscle Mass %,) assessed by BIA
timeFrame: Baseline and Week 6
measure: Percentage Weight Loss (%WL)
timeFrame: Baseline and Week 6
measure: Percentage Excess Weight Loss (%EWL)
timeFrame: Baseline and Week 6
Secondary outcomes:
measure: Change in Fasting Blood Glucose (mg/dL)
timeFrame: Baseline and Week 6
measure: Change in Fasting Insulin (µIU/mL)
timeFrame: Baseline and Week 6
measure: Change in Lipid Profile (HDL, LDL, Total Cholesterol, Triglycerides) (mg/dL)
timeFrame: Baseline and Week 6
measure: Change in Renal Function Markers (BUN, Creatinine, Uric Acid, Urea) (mg/dL)
timeFrame: Baseline and Week 6
measure: Change in Liver Function Tests (ALT, AST, Albumin, Total Protein) (U/L, g/dL)
timeFrame: Baseline and Week 6
measure: Change in Vitamin and Mineral Status (Vitamin B12, Folic Acid, Magnesium, Calcium, Sodium, Potassium) (ng/L, mg/dL, mmol/L, etc.)
timeFrame: Baseline and Week 6
measure: Change in Hematological Parameters (Hemoglobin, Hematocrit, Ferritin, Serum Iron, TIBC) (g/dL, µg/L, etc.)
timeFrame: Baseline and Week 6
measure: Change in Daily Energy and Macronutrient Intake
timeFrame: Baseline and Week 6
measure: Change in Micronutrient Intake
timeFrame: Baseline and Week 6
Other outcomes:
Locations:
city: Nilüfer
country: Turkey
facility: Özel Nev FSM Hastanesi
state: Bursa
city: Bursa
country: Turkey
facility: Özel Nev FSM Hastanesi
Study officials:
References: