The SAVOR Study: Appetite and Physiological Responses (SAVOR)

Seniors' Appetite: Vibrant Opportunities for Revitalization (SAVOR)

The study aims to identify key physiological factors that differentiate older adults with healthy appetites from those experiencing appetite decline. The investigators hypothesize that seniors experiencing appetite decline will exhibit distinct oro-sensory, gastrointestinal, and hormonal profiles compared to seniors with healthy appetites, suggesting underlying biological mechanisms contributing to reduced appetite.

Study Overview

• Status: Not yet recruiting
• Conditions: Malnutrition or Risk of Malnutrition; Anorexia of Aging
• Intervention / Treatment: Other: Shredded Chicken Congee

Detailed Description

Appetite decline in older adults, or anorexia of aging, is a prevalent geriatric syndrome associated with decreased quality of life, increased risk of malnutrition, and accelerated decline in health. While current nutritional guidelines often emphasize increasing nutrient density, these strategies often fail to address the root causes of diminished appetite. Emerging research highlights the critical role of age-related physiological changes, particularly dysregulation of the gut-brain axis, altered sensory perception, and hormonal imbalances, in suppressing appetite. Notably, existing evidence is largely derived from Western populations, which may not fully reflect the influence of cultural and lifestyle factors on appetite in Asian seniors. This leaves a significant gap in understanding and addressing appetite loss within this specific demographic. This study aims to address this gap by comprehensively investigating the physiological mechanisms underlying appetite regulation in Asian seniors, to identify key determinants that differentiate individuals with healthy appetites from those experiencing a decline. By assessing the relationships between oro-sensory function, gastric dynamics, neuro-hormonal regulation, gut microbiome composition and subjective appetite, this study seeks to provide a deeper understanding of the biological pathways driving appetite differences in this population. The findings of this study will lay the groundwork for future research aimed at developing culturally sensitive and effective interventions that can restore appetite, improve nutritional status, and ultimately enhance the health span and quality of life for older adults in Singapore and beyond. Furthermore, this work has the potential to drive innovation in the food and nutrition industry, leading to the development of tailored products and dietary strategies that effectively address the unique nutritional needs of aging populations, ultimately impacting public health recommendations and policies related to senior nutrition.

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Rina Quek, MSc; Phone Number: 64074379; Email: rina_quek@a-star.edu.sg
• Study Contact Backup: Name: Ashley Yu, BSc; Email: ashley_yu@a-star.edu.sg

Study Locations

• Singapore
  • Singapore, Singapore
    • Clinical Nutrition Research Centre
    • Contact: Darel Toh, PhD; Phone Number: 64074149; Email: darel_toh@a-star.edu.sg
    • Contact: Rina Quek, MSc; Email: rina_quek@a-star.edu.sg

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Postmenopausal female
• Aged 65-74 years
• Habitual breakfast consumer (consumes breakfast between 7am to 10am)
• Willingness to consume meals and follow intervention protocol
• English speaking

Exclusion Criteria:

• BMI ≥ 27.5
• Diagnosed with medical condition that may influence appetite or microbiome (e.g. diabetes, thyroid disorders, gastrointestinal diseases)
• Currently taking any medications or supplements that may influence appetite or the microbiome (e.g. probiotics, antibiotics, appetite stimulants/suppressants) one month prior to their first visit in consultation with study physician, PI and study team
• Following a special diet for weight management (e.g. low-calorie, low carbohydrate)
• History of bariatrics surgery
• Intentional attempt to change body weight or composition
• History of severe vasovagal syncope (blackouts or near faints) following blood draw
• Drug abuse within last 5 years
• Excessive alcoholic beverage consumption > 2 servings per day (1 serving defined as 360 mL beer, 150 mL wine or 45 mL distilled spirits)
• Smoking (cigarette, e-cigarette, cigar, pipe, vape)
• Engaging in habitual vigorous physical activity (as defined by physical activity questionnaire-PAQ)
• Loose teeth or jaw pain
• Not missing > 2 non-wisdom molars
• Involvement in other clinical studies that may influence the outcome of the study
• A study team member or their immediate family member

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Chicken porridge; Rice congee with shredded chicken and vegetable oil	Other: Shredded Chicken Congee; This is a mixed meal tolerance test intended to elicit gut hormone responses reflective of real-world dietary patterns.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ad Libitum Lunch	Participants will be asked to eat as much of the stir-fried beehoon as they want until they are comfortably full, to measure the exact calorie intake by weighing the food before and after eating.	Participants will be given 30 minutes to consume the meal until they are comfortably full, 180 minutes after the start of the intervention.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Palatability questionnaire	Palatability appetite questionnaire, rated on a visual analogue scale is a psychometric assessment tool where participants rate their subjective sensory experience-such as taste, smell, or pleasantness-by marking a point along a continuous 100 mm line anchored by opposing extremes (e.g., "extremely unpleasant" to "extremely pleasant").	Administered after consuming test meal and after consuming the ad libitum meal.
Appetite hormones	GLP-1, PYY and Acyl-ghrelin will be used to measure hormones related to appetite.	Blood samples will be collected at timepoints (t = -15 minute (baseline), 30, 60, 90, 120 and 180 minutes)
Subjective Appetite Questionnaire	A subjective appetite questionnaire utilizes a Visual Analogue Scale to quantify a person's current metabolic state by measuring four key sensations: hunger, fullness, desire to eat, and prospective food consumption.	Measurement is taken at t = -15 minute (baseline), 10, 30, 60, 90, 120 and 180 minutes
Gastric Ultrasound	Gastric ultrasound will measure the gastric emptying rate postprandially.	Measurements will be taken at t = -15 minute (baseline), 15, 45, 105 and 165 minutes
Stool collected using the OMNIgene and OMNImet	Stool sample will be collected in the OMNIgene-GUT and OMNImet-GUT tube for measurements that may include microbiome profiling, untargeted and targeted metabolome (e.g. bile acids and short-chain fatty acids profiling).	Baseline stool sample will be collected once between screening and intervention day.
Olfactory Acuity (SCENTinel)	Olfactory acuity will be assessed using a simple, non-invasive SCENTinel rapid smell test. Participants will be presented with test cards containing various odors, and will be asked to detect, rate, and identify the odors. The test assesses the participant's ability to perceive and recognize smells, providing information on their overall sense of smell.	Baseline measurement administered once during screening, takes approximately 5-10 minutes
Taste Acuity Test (WETT)	The Waterless Empirical Taste Test (WETT) is a sensory method for assessing how well participants can recognise and detect basic tastes. Participants will taste pre-moistened, paper-based test strips for the five basic tastes: sweet, sour, salty, bitter, and umami.	Baseline measurement administered once during screening, takes approximately 10-15 minutes
Blood plasma (Cytokines)	Blood samples may also be analyzed for indicators of inflammation including cytokines testing	t = -15 minute (baseline), 30, 60, 90, 120, 180 minutes
Blood plasma (Bile acids and short-chain fatty acids profiling)	Blood samples collected may be used to analyse biomarkers related to nutrition and digestive health e.g. bile acid and short-chain fatty acids profiling	t= -15 minute (baseline), 30, 60, 90, 120, 180 minutes
Bite Strength	Bite strength will be measured using a bite force device (non-invasive) that records the maximum force a participant can exert while biting. Multiple measurements will be taken with rest periods in between to prevent fatigue.	Baseline measurement that may be administered once during screening or test session, as schedule and equipment permits. Takes only a few minutes.
Tongue Strength (Tongue Pressure)	Tongue pressure will be measured using a device equipped with a disposable air-filled bulb placed between the tongue and the hard palate. Participants will be instructed to press the bulb with their tongue as firmly as possible for a few seconds. Multiple measurements will be taken with rest periods in between to ensure accuracy and prevent fatigue.	Baseline measurement that may be administered once during screening or test session, as schedule and equipment permits. Takes approximately 5 minutes.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Health and Lifestyle questionnaire	This questionnaire is to evaluate the participant's eligibility for the study. It consist of participant information, medical and health history, lifestyle and diet, physical activity.	Baseline measurement that is completed during screening visit
3-day food record	A 3-day food record is a detailed diary where participants document everything they eat and drink over two weekdays and one weekend day to provide an accurate snapshot of their typical nutritional intake. This is done using household measures (or digital scales), where exact portion sizes, cooking methods and brand names of all items are used.	Administered between screening and actual test session, to be completed on 2 weekdays and 1 weekend.
Gastrointestinal Symptom Rating Scale (GSRS)	The Gastrointestinal Symptom Rating Scale (GSRS) is a validated 15-item questionnaire used to assess the presence and severity of common digestive issues across five key areas: abdominal pain, reflux, diarrhea, constipation, and indigestion. Participants rate each symptom on a 7-point Likert scale-ranging from "no discomfort" to "very severe discomfort"-to provide a quantifiable measurement of their gastrointestinal well-being.	Baseline measurement administered once during screening.
Council on Nutrition Appetite Questionnaire (CNAQ)	The Council on Nutrition Appetite Questionnaire (CNAQ) is a brief, 8-item screening tool designed to predict future weight loss by assessing a participant's appetite and dietary habits. It asks about sensations like hunger, how quickly a participant feel full, and how food tastes to determine if a participant is at risk for nutritional deficiencies or significant weight changes over the coming months.	Baseline measurement administered once during screening, takes approximately 5-10 minutes
Pittsburgh Sleep Quality Index (PSQI)	The Pittsburgh Sleep Quality Index (PSQI) is a validated 19-item questionnaire used to measure sleep quality and disturbances over a one-month timeframe. It evaluates seven key areas-including sleep duration, how long it takes to fall asleep, sleep disruptions, and daytime tiredness-to generate a single overall score that differentiates between "good" and "poor" sleepers in clinical research.	Baseline measurement administered once during screening, takes approximately 5-10 minutes
Geriatric Depression Scale (GDS)	The Geriatric Depression Scale (GDS) is a 30-item questionnaire-often shortened to a 15-item version-specifically designed to screen for depression in older adults. Unlike general depression scales, it uses a simple "yes" or "no" format and focuses primarily on psychological and mood-related symptoms rather than physical complaints (like aches or fatigue), which can often overlap with normal aging or other medical conditions.	Administered once during screening, takes approximately 5 minutes
Dutch Eating Behavior Questionnaire (DEBQ)	The Dutch Eating Behavior Questionnaire (DEBQ) is a 33-item psychometric scale used to assess the distinct psychological factors and eating styles that can lead to overeating or weight gain. It breaks eating behaviors down into three core subscales - emotional eating, external eating and restrained eating.	Baseline measurement administered once during screening, takes approximately 10 minutes
Leeds Food Preference Questionnaire (LFPQ)	The Leeds Food Preference Questionnaire (LFPQ) is a computer-based tool used in behavioral research to measure different psychological components of food preference and appetite. It uses a series of food images to evaluate two distinct aspects of food reward: explicit liking and implicit wanting. The tool categorizes these preferences across different food characteristics, specifically comparing high-fat vs. low-fat foods, and sweet vs. savory tastes.	Baseline measurement administered once during screening, takes approximately 10-15 minutes
Three-Factor Eating Questionnaire (TFEQ)	The Three-Factor Eating Questionnaire (TFEQ) is a validated psychometric tool used to measure three distinct dimensions of human eating behavior and cognitive dietary control. It evaluates eating habits across three primary subscales: cognitive restraint, disinhibition and hunger	Baseline measurement administered once during screening, takes approximately 10 minutes
International Physical Activity Questionnaire (IPAQ)	The International Physical Activity Questionnaire (IPAQ) is a validated tool that measures a person's physical activity levels over a 7-day period. It records the total time spent across four distinct intensities: vigorous activity (like running or heavy lifting), moderate activity (like steady cycling), walking, and weekday sitting time. These tracked minutes are converted into a standard metabolic score (MET-minutes/week), which is then used to classify an individual's overall physical activity level into one of three distinct categories: Low, Moderate, or High.	Baseline measurement administered once during screening, takes approximately 10 minutes

Collaborators and Investigators

• Sponsor: Singapore Institute of Food and Biotechnology Innovation
• Investigators: Principal Investigator: Darel Toh, PhD, Clinical Nutrition Research Centre

Publications and helpful links

General Publications

• Sturm K, MacIntosh CG, Parker BA, Wishart J, Horowitz M, Chapman IM. Appetite, food intake, and plasma concentrations of cholecystokinin, ghrelin, and other gastrointestinal hormones in undernourished older women and well-nourished young and older women. J Clin Endocrinol Metab. 2003 Aug;88(8):3747-55. doi: 10.1210/jc.2002-021656.
• Dagbasi A, Warner J, Catterall V, Smith K, Crabtree DR, Carroll B, Frost G, Holliday A. Augmented gut hormone response to feeding in older adults exhibiting low appetite. Appetite. 2024 Oct 1;201:107415. doi: 10.1016/j.appet.2024.107415. Epub 2024 May 16.
• Atalayer D, Astbury NM. Anorexia of aging and gut hormones. Aging Dis. 2013 Oct 1;4(5):264-75. doi: 10.14336/AD.2013.0400264.
• Dagenais S, Fielding RA, Clark S, Cantu C, Prasad S, Groarke JD. Anorexia in Medicare Fee-for-Service Beneficiaries: A Claims-Based Analysis of Epidemiology and Mortality. J Nutr Health Aging. 2023;27(3):184-191. doi: 10.1007/s12603-023-1882-4.
• Morley JE. Peptides and aging: Their role in anorexia and memory. Peptides. 2015 Oct;72:112-8. doi: 10.1016/j.peptides.2015.04.007. Epub 2015 Apr 17.

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): October 1, 2026

Study Registration Dates

• First Submitted: May 20, 2026
• First Submitted That Met QC Criteria: June 3, 2026
• First Posted (Actual): June 9, 2026

Study Record Updates

• Last Update Posted (Actual): June 9, 2026
• Last Update Submitted That Met QC Criteria: June 3, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: elderly; malnutrition; appetite regulation; appetite decline; anorexia of aging; Asian seniors
• Additional Relevant MeSH Terms: Nutrition Disorders; Nutritional and Metabolic Diseases; Malnutrition
• Other Study ID Numbers: 2025-133

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No