Adiposity, Decision-Making, Insulin Sensitivity/Resistance, Reward Learning
Conditions
Keywords
flavor nutrient learning, insulin sensitivity, adiposity, decision-making, probabilistic learning
Brief summary
Reward learning and decision-making processes, which operate largely outside of conscious control, shape food choices and eating behaviors. Excess adiposity is associated with differences in brain structure and functional connectivity underlying these processes, and insulin resistance, which commonly co-occurs with excess adiposity, has been linked with dopamine signaling that is crucial for these processes. However, whether and how excess adiposity and insulin resistance affect reward learning and decision-making remains poorly understood. This study will address that gap, examining the effects of excess adiposity and insulin resistance, and their interaction, on processes of reward learning and decision-making in food-specific and general contexts.
Interventions
OTHERBeverage: Conditioned Stimulus -
Participants will consume flavored beverage solutions sweetened with sucralose during 6 conditioning sessions.
OTHERBeverage: Conditioned Stimulus +
Participants will consume flavored beverage solutions sweetened with sucralose and containing 110 calories of maltodextrin during 6 conditioning sessions.
Sponsors
Virginia Polytechnic Institute and State University
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* 18 to 45 years of age * Self-reported weight stable (within 5 lbs) for previous 3 months * Not pregnant or planning to become pregnant during study participation * Weigh more than 110 lbs (due to blood draws used in study) * Residing in Roanoke, VA, area and/or willing to attend sessions at the Fralin Biomedical Research Institute
Exclusion criteria
* BMI \< 18.5 or \> 40 kg/m2 * Hemoglobin A1c \> 6.4% * Fasting blood glucose \> 126 mg/dL * 2-hour blood glucose \> 200 mg/dL * Self-reported current diagnosis of diabetes or other endocrine/metabolic disorder * Self-reported current inhaled nicotine use * Self-reported history of alcohol dependence * Self-reported use of medications known to influence study measures (including antiglycemic agents, thyroid medications, etc.) * Self-reported neurological or psychological disorder * Self-reported claustrophobia or discomfort with mock fMRI training * Self-reported history of head injury resulting in loss of consciousness for more than 10 minutes * Contraindications to MRI, including pacemaker, aneurysm clip, neurostimulator, cochlear implant, metal in eyes, steel worker, other implants * Self-reported previous metabolic/weight loss surgery * Self-reported adherence to special or restrictive diet within the past 3 months (e.g., low-carb, ketogenic, exclusion of food groups/specific macronutrients, etc.) * Self-reported allergy to ingredient used in the study drinks
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Rated Liking | On the first day of enrollment to the post-test session approximately 1-2 weeks later | Participants will rate liking of flavors that will be paired with conditioned stimulus (CS) + and CS- drinks on a labeled hedonic scale during an enrollment session. In a post-test session, after all conditioning sessions have occurred, participants will rate liking of flavors that were previously paired with CS+ and CS- drinks. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Rated Wanting | On the first day of enrollment to the post-test session approximately 1-2 weeks later | Participants will rate wanting of flavors that will be paired with conditioned stimulus (CS) + and CS- drinks on a visual analog scale during an enrollment session. In a post-test session, after all conditioning sessions have occurred, participants will rate wanting of flavors that were previously paired with CS+ and CS- drinks. |
| Proportion Correct on a Probabilistic Learning Task | Approximately 30-45 minutes during the enrollment/screening session at the start of the study | Participants will complete a probabilistic learning task in which they choose between abstract stimuli and observe probabilistic outcomes with the goal of maximizing accuracy. The proportion of trials in which the objectively optimal choice has been selected will be computed as the proportion correct. |
Outcome results
None listed