An observational study in Obesity, Taste Disorders and Smell Disorder, sponsored by Hanife Köksal. Completed at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2025-12-17.
Sponsored by Hanife Köksal · Observational
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.
Obesity is a chronic, multifactorial disease that negatively impacts health and quality of life. Bariatric surgery is an effective treatment option for severe obesity, leading to significant and sustained weight loss as well as improvement in obesity-related comorbidities.
Postoperative changes in taste and smell perception are frequently reported by bariatric patients and may influence food preferences, hedonic hunger, and overall diet quality. These sensory alterations can result from anatomical and hormonal changes after surgery, including altered gut hormone secretion (e.g., PYY, GLP-1, ghrelin) and bile acid metabolism, which affect appetite regulation and reward pathways.
This cross-sectional observational study evaluated adults aged 18-65 years who had undergone sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) at least three months prior to enrollment. Data collection included sociodemographic and health information, dietary habits, a modified 33-item taste and smell questionnaire, the Power of Food Scale (PFS) to assess hedonic hunger, the Mediterranean Diet Adherence Screener (MEDAS), the International Physical Activity Questionnaire (IPAQ), and anthropometric measurements. Nutrient intakes were analyzed according to the Türkiye Nutrition Guide (TÜBER-2022) reference values.
The primary objective was to determine the relationship between postoperative taste/smell changes and hedonic hunger. Secondary objectives included assessing the association between sensory perception and Mediterranean diet adherence, anthropometric parameters, and nutrient adequacy by surgery type. Findings from this study may guide the development of personalized nutritional follow-up protocols to improve long-term outcomes in bariatric patients.
11,522 studies on the registry are indexed under Obesity; 2,033 are open to participants now.
This study's enrollment of 101 is below the median of 114 across 2,154 observational studies indexed under Obesity.
Browse Obesity studies →This is the only study on the registry with Hanife Köksal as lead sponsor.
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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.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants who underwent sleeve gastrectomy at least 3 months prior to enrollment.
Other: Sleeve Gastrectomy (SG) and 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)
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.
Power of Food Scale (PFS) Score
Hedonic hunger assessed using the Power of Food Scale (range: 1-5; higher scores indicate greater hedonic hunger).
Time frame: 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).
Time frame: Baseline (≥3 months after bariatric surgery, at study enrollment)
Mediterranean Diet Adherence Screener (MEDAS) Score
Adherence to the Mediterranean diet assessed using the 14-item MEDAS questionnaire (range: 0-14; higher scores indicate greater adherence).
Time frame: Baseline (≥3 months after bariatric surgery, at study enrollment)
Body Mass Index (BMI)
BMI calculated as weight (kg) / height (m²).
Time frame: Baseline (Day 1, at study enrollment)
Waist-to-Hip Ratio (WHR)
WHR calculated as waist circumference (cm) / hip circumference (cm).
Time frame: Baseline (Day 1, at study enrollment)
Energy Intake Adequacy (% of TÜBER-2022 reference)
Daily energy intake adequacy compared to TÜBER-2022 reference values.
Time frame: Baseline (Day 1, at study enrollment)
Protein Intake Adequacy (% of TÜBER-2022 reference)
Daily protein intake adequacy compared to TÜBER-2022 reference values.
Time frame: Baseline (Day 1, at study enrollment)
Micronutrient Intake Adequacy (e.g., iron, folate, vitamin E; % of TÜBER-2022 reference)
Micronutrient intake adequacy compared to TÜBER-2022 reference values.
Time frame: Baseline (Day 1, at study enrollment)
Nutrient Adequacy Score (based on TÜBER-2022 reference values)
Composite score reflecting the percentage adequacy of daily energy, macronutrient, and micronutrient intakes compared to TÜBER-2022 reference values. Higher scores indicate greater adequacy.
Time frame: Baseline (Day 1, at study enrollment)
Plan to share: No — No - Individual participant data (IPD) will not be shared due to privacy concerns and lack of prior consent for public data sharing from study participants. Only aggregated results will be available in publications.
No publications or documents are linked to this record.
Ran from Jan 2024 to primary completion in Nov 2024, 10 months.
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This study is completed, as verified in Dec 2025. You cannot join it, but the record below documents what was studied.
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