The goal of this study is to quantify energy metabolism using indirect calorimetry at rest, in the presence of excess energy following a meal, and in response to the demand for energy during exercise. The investigators also will examine the individual and joint associations of activity and obesity status on neurocognitive domains of appetite control. Participants will include adolescent males and females (N=80) using a 2 x 2 cross-sectional study design, stratified by body weight (normal vs overweight/obese) and physical activity level (sedentary vs. active).

The investigators hypothesize that low levels of fitness and MVPA result in impaired metabolic function in adolescents. For this pilot study, the investigators will quantify variations in metabolic characteristics using a 2 x 2 cross-sectional study design, stratified by body weight (normal vs overweight/obese) and physical activity (sedentary vs. active). The goal is to identify metabolic factors that influence the energy balance system to directly inform interventions designed to prevent or reduce the prevalence of pediatric obesity.

Inclusion Criteria:

• Males (Tanner Stage III-IV), ages 14-18
• Weight stable (5% weight change) over the previous three months as assessed by self-report.
• BMI greater than 5th and less than 99th percentile
• Physically healthy for exercise as assessed by self report Physical Activity Readiness Questionnaire (PAR-Q) for children.
• For fMRI testing, all participants must be right handed and must have normal or corrected to normal vision (as they will be viewing pictures in the fMRI procedure).

Exclusion Criteria:

• History of restrained eating, eating disorders, bariatric surgery, or other significant medical diagnosis that could impact metabolism.
• Participants taking thyroid medications, beta blockers, or other stimulants (medications are known to affect physical activity level and metabolism).
• Due to fMRI procedure requirements, children with a history of Attention Deficit Hyperactivity Disorder (ADHD) or other diagnosed psychiatric issues will be excluded.

Participants will include 60 adolescent males (aged 14-18 years, Tanner stages III- IV), equally enrolled based on physical activity and body weight status.

aggregate results will be shared