The Relationship Between Olfactory and Gustatory Senses, Hedonic Hunger, and Diet Quality After Bariatric Surgery

NCT07290075 | Completed

• 1 other identifier: USK-NUTR-HK01
• Study Type: observational
• Target: 101
• Locations: 1 country
• Sites: 1

Brief Summary

This cross-sectional observational study investigates the association between changes in olfactory and gustatory senses and hedonic hunger among individuals who have undergone bariatric surgery. The study also examines the effects of these sensory changes on diet quality and anthropometric measurements. Participants completed a structured questionnaire including sociodemographic and health information, dietary habits, a modified 33-item taste and smell assessment, the Power of Food Scale (PFS), the Mediterranean Diet Adherence Screener (MEDAS), the International Physical Activity Questionnaire (IPAQ), and anthropometric measurements.

Conditions

Obesity; Taste Disorders; Smell Disorder

Keywords

Hedonic Hunger; bariatric surgery outcomes; Mediterranean Diet; Nutrient Adequacy; Power of Food Scale (PFS); Taste and Smell Questionnaire; MEDAS

Outcome Measures

Primary Outcomes (2)

• Power of Food Scale (PFS) Score

  Hedonic hunger assessed using the Power of Food Scale (range: 1-5; higher scores indicate greater hedonic hunger).

  Baseline (Day 1, at study enrollment)

• Modified 33-item Taste and Smell Questionnaire Score

  Changes in taste and smell perception assessed using a modified 33-item questionnaire (range: 0-33; higher scores indicate more pronounced sensory changes).

  Baseline (≥3 months after bariatric surgery, at study enrollment)

Secondary Outcomes (7)

• Mediterranean Diet Adherence Screener (MEDAS) Score

  Baseline (≥3 months after bariatric surgery, at study enrollment)

• Body Mass Index (BMI)

  Baseline (Day 1, at study enrollment)

• Waist-to-Hip Ratio (WHR)

  Baseline (Day 1, at study enrollment)

• Energy Intake Adequacy (% of TÜBER-2022 reference)

  Baseline (Day 1, at study enrollment)

• Protein Intake Adequacy (% of TÜBER-2022 reference)

  Baseline (Day 1, at study enrollment)

Study Arms (2)

Sleeve Gastrectomy (SG)

Participants who underwent sleeve gastrectomy at least 3 months prior to enrollment.

Other: Sleeve Gastrectomy (SG) and Roux-en-Y Gastric Bypass (RYGB)

Roux-en-Y Gastric Bypass (RYGB)

Participants who underwent Roux-en-Y gastric bypass at least 3 months prior to enrollment.

Other: Sleeve Gastrectomy (SG) and Roux-en-Y Gastric Bypass (RYGB)

Interventions

Sleeve Gastrectomy (SG) and Roux-en-Y Gastric Bypass (RYGB) OTHER

Participants who have undergone sleeve gastrectomy ≥3 months prior to study enrollment; and Participants who have undergone Roux-en-Y gastric bypass ≥3 months prior to study enrollment.

Roux-en-Y Gastric Bypass (RYGB); Sleeve Gastrectomy (SG)

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Adults aged 18-65 years who have undergone bariatric surgery (Sleeve Gastrectomy or Roux-en-Y Gastric Bypass) at least 3 months prior to enrollment, recruited from patients followed in clinical nutrition and bariatric surgery outpatient clinics.

You may qualify if:

• Adults aged 18 to 65 years
• History of bariatric surgery (Sleeve Gastrectomy or Roux-en-Y Gastric Bypass)
• At least 3 months post-surgery at the time of study enrollment
• Able and willing to provide informed consent

You may not qualify if:

• Pregnancy
• History of neurological disorders affecting taste or smell
• Active upper respiratory infection at the time of assessment
• Severe psychiatric disorders that may impair participation

Sponsors & Collaborators

• Hanife Köksal: lead
• Uskudar University: collaborator

Study Sites (1)

Istanbul University, Faculty of Medicine, Department of Endocrinology and Metabolism

Istanbul, Capa, 34093, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Obesity; Taste Disorders; Olfaction Disorders

Interventions

Gastric Bypass

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Sensation Disorders; Neurologic Manifestations; Nervous System Diseases

Intervention Hierarchy (Ancestors)

Bariatric Surgery; Bariatrics; Obesity Management; Therapeutics; Gastroenterostomy; Anastomosis, Surgical; Surgical Procedures, Operative; Digestive System Surgical Procedures

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Registered dietitians

Study Record Dates

• First Submitted: August 12, 2025
• First Posted: December 17, 2025
• Study Start: January 1, 2024
• Primary Completion: November 30, 2024
• Study Completion: January 31, 2025
• Last Updated: December 17, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)