Specificity of Flavor-Nutrient Learning: An fMRI Experiment
Condition: Feeding Behavior; Inhibition (Psychology)
Study type: Interventional

Summary: 
      This is an etiology study designed to examine the how people's brains and behaviors respond
      to regularly consuming a beverage. Participants are assessed at 2 behavioral assessments
      (Wave 1 and Wave 2), 2 scans (at the BRIC), and at 9 'intervention' assessments (5-10mins)
      different time periods throughout the study. At their first assessment (W1) they are
      randomized into one of two juices.
    

Detailed description: 
      Study design and Participants The investigators randomly assigned participants to consume one
      of two novel flavored, high-sugar beverages daily for a 3-week period. The study included
      fMRI and behavioral assessments pre-/post-intervention and 9 study visits during the
      intervention period. 20, healthy-weight, young adults (10 female, 10 male; x̅ age = 23.3±3.4;
      x̅ BMI = 22.1±1.9; 5% Hispanic,10% Asian/Pacific Islanders, 85% European Americans) completed
      protocol seen in Figure 1a. Exclusion criteria were a body mass index (BMI; kg/m2) <18.5 or
      >26.5, sweetened (artificial or caloric) beverage consumption > 6 times/week,
      tobacco/e-cigarette use > 6 times/week, psychoactive medications or drugs more than > 1
      time/month, pregnancy, head injury with a loss of consciousness, significant cognitive
      impairment, major medical problems, endorsement of disordered eating or current Axis I
      psychiatric disorder as assessed by online screener. Participants provided written informed
      consent; methods and procedures were approved by University of North Carolina at Chapel
      Hill's Institutional Review Board.

      Intervention Interested participants completed a brief online screening survey those that
      appeared to qualify were scheduled for the baseline visit where inclusion and exclusion were
      confirmed and consent was reviewed and obtained. Participants were randomly assigned to one
      of the two juice conditions, stratified by sex. Once consented, participants completed the
      behavioral and perceptual measures at the baseline behavioral assessment. On a separate day
      participants completed the baseline neuroimaging assessment. The day following the
      neuroimaging assessment participants began the intervention period where they consumed their
      assigned juice daily for the 3-week period. During the intervention period participants came
      to our lab every Monday, Wednesday and Friday (9 total assessments) to: consume a portion of
      that day's juice in the lab, complete perceptual measures and a weight assessment, pick up
      the following day(s) juice, and return the empty bottles from the previous day(s). On
      Fridays, participants were given two bottles to consume and instructed to consume one per day
      and return the bottles on the following Monday. Empty bottles were returned to increase
      compliance. The follow-up neuroimaging assessment was scheduled such that participants
      completed the 3-week intervention, did not consume a juice for 24 hours and then were
      scanned. The follow-up behavioral assessment occurred within three days of the follow-up scan
      Figure 1b.

      Beverages were selected to be: sweetened from sugar, i.e., not include high fructose corn
      syrup, and/or artificial sweeteners, have no artificial flavors, colors or preservatives,
      calorically equivalent to common sugar-sweetened beverages (e.g., soft drinks), be caffeine-
      and texture-free, and generally novel in flavor. The juices were eucaloric, had similar
      palatability, and easily distinguishable from one another. Prior to study initiation, pilot
      taste testing was completed in a small sample to insure both the novelty and equal
      palatability of the two juices to be included in the study. The resulting two beverages were:
      Apple-Cherry-Berry juice and Orange-Tangerine-Passionfruit juice. The 10 fl oz bottles of
      juice each contained 133 kcals, 31g of sugar. The juice logos were selected to be novel, of
      similar visual complexity, both in black and white, convey no information beyond a unique
      symbol, yet be easily distinguishable from one another. Each juice was presented in
      individual 10 fl oz bottles with the only identifier a sticker of the associated logo.
    

Intervention name(s): Juice A; Juice B
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Subjects to be given juice daily for 3 weeks.; Subjects to be given juice daily for 3 weeks.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Basic Science