Brain, Appetite, Teens, and Exercise
Condition: Energy Balance; Appetitive Behavior; Obesity
Study type: Interventional

Summary: 
      The long-term goal is to develop effective, evidence-based lifestyle interventions to prevent
      and treat childhood obesity and related co-morbidities. The short-term goal, and the purpose
      of this application, is to quantify appetite and neural mechanisms of food reward in
      overweight/obese (OW/OB) sedentary youth and to quantify changes following the implementation
      of a physical activity intervention. The central hypothesis is that appetite becomes
      dysregulated at low levels of physical activity via neural reward pathways, and appetite
      control will improve following a long-term exercise intervention. The investigators consider
      this project a pilot study designed to generate data to be used for future external funding
      opportunities, demonstrate collaboration between researchers, and test the feasibility of the
      protocols.
    

Detailed description: 
      Specific Aim 1: To identify associations between neural, psychological, and hormonal appetite
      control pathways using subjective and objective measures of appetite and neurocognitive
      assessments of reward pre-intervention.

      Hypothesis 1: There will be significant cross-modulation of appetite across neural (brain
      activation), psychological (subjective hunger), and hormonal pathways (satiety biomarkers),
      though the temporal relationship between each in response to feeding is unknown.

      Specific Aim 2: To assess the effectiveness of a physical activity intervention on eating
      behavior in adolescents; OW/OB inactive adolescents will be randomly assigned to a 3-month
      exercise intervention (Exercise +Newsletter), or a control condition (Newsletter).

      Hypothesis 2a: Those exposed to the exercise intervention will have greater improvements
      (compared to control group) in appetite (subjective self-reported hunger and palatability
      responses, and, objectively, satiety and appetite hormones glucose, insulin, ghrelin, and
      leptin, and calories consumed during ad libitum meal).

      Hypothesis 2B. Compared to pre-intervention, OB/OW youth in the exercise group will show
      decreased reward activation in regions of the brain when making decisions about appetizing
      foods compared to post-intervention when hungry and when fed. In self-control regions,
      compared to pre-intervention, the investigators will observe increased activity in both
      hungry and fed conditions.

      At the end of the proposed study, it is the expectation that the investigators will have
      collected important preliminary data regarding how long-term structured exercise acts upon
      appetite and neural mechanisms related to food reward in adolescents. Findings are key not
      only to interventions targeting OW/OB youth, but also to public policy and health
      recommendations for the importance of physical activity in children.
    

Intervention name(s): Exercise Intervention; Newsletter
Intervention type(s): Behavioral; Behavioral
Intervention description(s): Youth randomized to the active condition will participate in an organized exercise program. During the exercise program, adolescents will participate in a supervised structured exercise (treadmill walking/cycling on stationary bike) on 3 days equivalent to approximately 180 min/week of moderate-intensity exercise. The rationale for this dose of structured exercise is based on national (ADA) and international physical activity recommendations for youth of 60 minutes/day.; Families will receive a monthly newsletter with "parenting tips, sample praise statements, and child-appropriate activities and recipes" identical to what has been used in the work of leaders in the field of pediatric obesity. Previous research suggests that newsletter/mail interventions are well received by participants and are frequently included in federally funded health intervention studies.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: To assess the effectiveness of a physical activity intervention on eating behavior in adolescents; OW/OB inactive adolescents will be randomly assigned to a 3-month exercise intervention (Exercise +Newsletter), or a control condition (Newsletter).
Masking: None (Open Label)
Primary purpose: Health Services Research