Appetite Lexicon Training

A fundamental limitation to the application of appetitive sensations is how they are measured. The most common approach relies on untrained individuals to self-report the sensations they experience under a given set of conditions. Investigators believe this is problematic because assumptions made about participant ratings are likely not valid. The proposed protocol will permit examination of whether training on appetite lexicon enhances the reliability of appetite ratings. Investigators also hypothesize that different preloads will induce different magnitudes of appetite sensations (hunger, fullness, desire to eat, and prospective consumption) depending on their energy density.

A fundamental limitation to the application of appetitive sensations is how they are measured. The most common approach relies on untrained individuals to self-report the sensations they experience under a given set of conditions. Investigators believe this is problematic because assumptions made about participant ratings are likely not valid. Most commonly, participants are asked to rate their hunger, desire to eat, fullness, and prospective consumption. For example, researchers have demonstrated that hunger and fullness stem from different physiological processes (e.g., different gut-peptides and neurotransmitters) and serve different purposes (eating initiation (hunger), meal termination (fullness)) and, accordingly, expect participants to rate the two sensations independently. However, participants treat them as opposite poles on a common continuum. Additionally, in focus group analysis, consumers often use researcher-defined distinct terms interchangeably (hunger=desire to eat; fullness =lack of desire to eat). However, the distinction between these sensations is clinically important. Hunger and fullness do not always change reciprocally and equally in clinical conditions. Hunger can change without a shift in fullness, and the reverse has also been reported. Investigators believe reporting sensitivity, selectivity, and reliability can be improved by training participants on the terminology of appetitive sensations prior to testing, just as any bench researcher would calibrate their instruments before measurements. The proposed protocol will permit examination of whether training on appetite lexicon enhances the reliability of appetite ratings. Investigators also hypothesize that different preloads will induce different magnitudes of appetite sensations (hunger, fullness, desire to eat, and prospective consumption) depending on their energy density.

Eligibility Criteria:
Inclusion Criteria:

1. BMI 18-25 kg/m2.
2. Age 18-60 years.
3. Body weight fluctuation of \<2.5kg in the past 3 months.
4. Fasting blood glucose below 6.1mmol/1 via capillary finger-stick blood sample using a SureStep glucometer (Lifescan, Milpitas, CA).
5. Regular eating pattern (i.e., reliable timing of eating events (±1 hour at least 5 days/wk - absolute pattern is less important than consistency.))
6. Willing to eat all test foods. Exclusion

Exclusion Criteria:

1. Having an acute disease.
2. Planning to initiate or terminate the use of medication known to affect appetite.
3. Diagnosed relevant chronic health conditions (e.g. diabetes, cardiovascular disease).
4. Allergies to eggs, peanuts, gluten, dairy, and carrots.
5. Age 61+ years