GLP-1, PYY and Acyl-ghrelin will be used to measure hormones related to appetite.

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.

Gastric ultrasound will measure the gastric emptying rate postprandially.

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).

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.

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.

Blood samples may also be analyzed for indicators of inflammation including cytokines testing

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

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.

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.

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.

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.

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.

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.

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.

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.

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

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.