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 nutritionalhabits and clinical outcomes (anthropometric and biochemical measurements) in patientswith insufficient weight loss (IWL) or weight regain (WR) after bariatric surgery, and tocompare these findings with those of a control group.
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.
Other: Diet
A four-stage dietary program will be implemented in accordance with ASMBS guidelines. To
the best of our knowledge, there is currently no study comparing the dietary approach
following revisional bariatric surgery with ketogenic and intermittent fasting diets
Other Name: bariatric diet
Other: Ketogenic diet
A high-protein Very Low-Calorie Ketogenic Diet (VLCKD) will be implemented as the
nutritional intervention. In line with previous studies, the daily energy intake of the
ketogenic diet 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. Total carbohydrate
intake will be restricted to less than 30 g per day, primarily from vegetables, while fat
intake will derive from natural protein sources and 10 g of olive oil per day.
Other: Fasting
Patients in this group will follow a time-restricted eating pattern (16/8) for a duration
of 6 weeks, with food intake limited to an 8-hour window each day. Intermittent fasting
will preferably be observed between 6:00 PM and 10:00 AM; however, patients may choose
alternative 16-hour fasting periods such as 7:00 PM-11:00 AM or 8:00 PM-12:00 PM,
depending on their individual routines. During the 8-hour feeding window, patients will
adhere to the stage 4 post-bariatric dietary guidelines in accordance with ASMBS
recommendations
Other Name: intermittent fasting
Other: Control
No individualized diet will be planned
Other Name: Control Group
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.
Özel Nev FSM Hastanesi
Nilüfer, Bursa, Turkey
Özel Nev FSM Hastanesi
Bursa, Turkey
Seher Dallı Şen, PhD Student, PhD Student
+905393919700
seher.dalli@std.medipol.edu.tr
Not Provided