Interventions for Weight Regain After Bariatric Surgery

Medipol University

Status: Not yet enrolling

Conditions: Revisional Bariatric Surgery; Obese Patients (BMI ≥ 30 kg/m²); Obese Patients With Bariatric Surgery; Ketogenic Dieting; Intermittent Fasting; Weight Regain Post Bariatric Surgery

Treatments: Other: Control; Other: Diet; Other: Ketogenic diet; Other: Fasting

Study type: Interventional

Funder types: Other

Identifiers

NCT06963437

MEDU-SBE-SS-01

Details and patient eligibility

About

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.

Full 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.

Enrollment: 56 estimated patients

Sex: All

Ages: 18 to 45 years old

Volunteers: No Healthy Volunteers

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).

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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56 participants in 4 patient groups

Revisional bariatric surgery (RBS) group

Experimental group

Description:

A nutrition program in accordance with ASMBS guidelines will be implemented for patients undergoing revisional bariatric surgery.

Treatment:

Other: Diet

Very low-calorie ketogenic diet (VLCKD) group

Experimental group

Description:

The daily energy intake of VLCKD will be planned as 600-800 kcal, with approximately 10% of energy from carbohydrates (\<30 g/day), 40-45% from protein, and 40-50% from fat.

Treatment:

Other: Ketogenic diet

Intermittent fasting (IF) group

Experimental group

Description:

Time-restricted intermittent fasting (16/8) will be applied. Patients in this group will follow a feeding schedule limited to an 8-hour window (16/8) for a duration of 6 weeks.

Treatment:

Other: Fasting

Control group

Active Comparator group

Description:

No individualized diet will be planned; instead, patients will receive education on the stage 4 dietary guidelines recommended for lifelong adherence following bariatric surgery.

Treatment:

Other: Control