Level Up! (The Combined and Independent Effects of Exercise Training and Dietary Enhancement on Cardiometabolic Health in Adolescents With Obesity)

The Level Up! study is a 12-week randomized controlled trial designed to investigate the independent and combined effects of exercise training and dietary enrichment on cardiometabolic health in adolescents with obesity. The study will enroll adolescents participating in an obesity treatment program. Participants will be randomly assigned to one of four groups: standard of care, exercise, dietary, or combined exercise and dietary intervention.

Each participant will attend three assessment visits at baseline, week 6, and week 12 at the Arkansas Children's Nutrition Center (ACNC). The following key measurements will be conducted:

• Body Composition: Dual-Energy X-ray Absorptiometry (DXA)
• Metabolic Profile: Fasting blood markers, including glucose, lipid profile, and insulin resistance
• Vascular Function: Brachial artery flow-mediated dilation (ultrasound)
• Liver Fat Content: Elastography
• Continuous Glucose Monitoring: Interstitial sensor-based glucose measurement
• Resting Metabolic Rate: Indirect calorimetry
• Aerobic Capacity: Cardiopulmonary exercise test (spirometry)
• Muscle Strength: Dynamometry
• Physical Activity & Sleep: Accelerometry
• Dietary Intake: 3-day food records

Inclusion criteria

• Male or female aged 13 to 17 years.
• Newly enrolled in a weight management program.
• Excessive weight: Class I obesity I (≥95% percentile to < 120% of the 95th percentile), class II Obesity (≥120 to <140% of the 95th percentile, or BMI ≥35 to < 40 g/m2).
• Less than 60 min/day of moderate to vigorous physical activity.
• Fruit intake ≤ 1.5 cup equivalent per day.
• Vegetable intake ≤ 1.5 cup equivalent per day.
• Medical release.

Exclusion criteria

• Type 2 diabetes mellitus.
• Asthma that requires daily use of inhalers to keep symptoms under control.
• Asthma that requires the use of rescue inhalers (e.g., albuterol) >2 days per week
• Exercise-induced asthma.
• Autism spectrum disorder (e.g., Autistic disorder, Rett disorder, Asperger disorder, childhood disintegrative disorder, pervasive developmental disorder not otherwise specified (PDD-NOS).
• Epilepsy.
• Cancer.
• Chronic kidney disease.
• Hormonal disease (e.g., hypothyroidism and growth hormone deficiency).
• Autoimmune diseases (e.g., lupus, thyroiditis, juvenile idiopathic arthritis).
• Bleeding disorders (e.g., hemophilia).
• Chronic infections (e.g., HIV, hepatitis B, hepatitis C).
• Other pre-existing medical conditions or medications as determined by the investigators to affect the outcomes of interest.
• Pregnancy.
• Dislike of > 1 study product assessed at the initial visit.
• Parent/child refusal to have blood drawn.
• Refusal to authorize study investigators to access data from the clinical records.