Eating Behavior, Nutritional Status and Appetite Hormones After Bariatric Surgery

Evaluation of Changes in Postoperative Eating Behavior Attitudes, Nutritional Status, and Some Hormonal Parameters Regulating Appetite in Surgical Weight Management

This study aims to evaluate changes in eating behavior attitudes, nutritional status, and appetite-regulating hormonal parameters in individuals who have undergone Laparoscopic Sleeve Gastrectomy (LSG). The study will be conducted at Bursa Yıldırım Doruk Hospital, Department of General Surgery. A total of 40 volunteer participants who underwent LSG within the last month will be included. Participants will be assessed at baseline (shortly after surgery) and at 6-month follow-up. Assessments will include anthropometric measurements (body weight, height, waist and hip circumference, BMI, waist-to-hip ratio), 3-day dietary intake records analyzed using BeBIS 8.2 software, and the Adult Eating Behavior Scale. Biochemical parameters including fasting blood glucose, total cholesterol, triglycerides, HDL, LDL, VLDL cholesterol, and insulin will be obtained from patient files and analyzed using Advia Chemistry 2400 and Advia XPT devices. Additionally, appetite-regulating hormones (ghrelin, GLP-1, PYY) will be analyzed from residual blood samples using the ELISA method with RelAssay Diagnostics kits by Teknogen Bioengineering Laboratory. All data will be compared between baseline and 6-month follow-up to evaluate the impact of bariatric surgery on nutritional and hormonal outcomes.

This observational study will be conducted at Bursa Yıldırım Doruk Hospital, General Surgery Clinic, under the supervision of Assoc. Prof. Dogukan Durak. Forty volunteer participants who underwent Laparoscopic Sleeve Gastrectomy (LSG) within the last month and meet the inclusion and exclusion criteria will be enrolled after signing an informed consent form.

Assessments will be performed at two time points: at baseline (shortly after surgery) and at 6-month follow-up.

Anthropometric Measurements: Body weight, height, waist and hip circumference will be measured. BMI and waist-to-hip ratio will be calculated accordingly. Waist circumference will be evaluated according to WHO criteria.

Dietary Assessment: A 3-day dietary intake record will be collected from each participant at both time points. Food portion sizes will be estimated using the "Food and Nutrient Photo Catalog." Energy and macronutrient intake will be analyzed using BeBIS 8.2 software and evaluated according to the Turkish Dietary Guidelines 2022 (TUBER 2022).

Eating Behavior Assessment: The Adult Eating Behavior Scale (developed by Celik et al.) will be administered at both time points. The scale consists of 18 items and 5 subscales, scored between 0-100. Higher scores indicate more positive attitudes toward eating behavior.

Biochemical and Hormonal Parameters: After 12-hour fasting, the following biochemical parameters will be obtained from patient files: fasting blood glucose (FBG), total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, very low-density lipoprotein (VLDL) cholesterol, and insulin. Routine biochemical parameters and lipid profile will be analyzed spectrophotometrically using the Advia Chemistry 2400 device, while insulin will be measured by chemiluminescence using the Advia XPT device. Additionally, appetite-regulating hormones including ghrelin, glucagon-like peptide-1 (GLP-1), and peptide YY (PYY) will be analyzed from residual blood samples stored at -20°C by Teknogen Bioengineering Laboratory using the ELISA method with an automated microplate reader (Biotek TS800) and RelAssay Diagnostics commercial kits (Ankara, Turkey).

All data will be compared between baseline and 6-month follow-up using appropriate statistical methods.

Inclusion Criteria:

• Having undergone Laparoscopic Sleeve Gastrectomy (LSG) within the last month
• Aged between 18-50 years
• Signing the informed consent form
• Having a Body Mass Index (BMI) of 40 kg/m2 or between 35-40 kg/m2 with obesity-related comorbidities
• No diagnosis of depression
• No eating behavior disorder
• No psychiatric disorder

Exclusion Criteria:

• Not having undergone Laparoscopic Sleeve Gastrectomy (LSG) or not planning to undergo bariatric surgery
• Not being in the age range of 18-50 years
• Not signing the informed consent form
• Having a Body Mass Index (BMI) greater than 40 kg/m2 or less than 35 kg/m2 without obesity-related comorbidities
• Having a diagnosis of depression
• Having an eating behavior disorder
• Having a psychiatric disorder