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

Summary

The goal of this clinical trial is to determine whether adding structured exercise training and a structured fruit and vegetable dietary program to standard multidisciplinary obesity care improves cardiometabolic health in adolescents with obesity enrolled in a weight management program. The main questions it aims to answer are: * Does adding structured exercise training to standard multidisciplinary obesity care improve cardiometabolic health? * Does adding a structured fruit and vegetable dietary program to standard multidisciplinary obesity care improve cardiometabolic health? * Does combining structured exercise training and the fruit and vegetable dietary program with standard multidisciplinary obesity care improve cardiometabolic health? Researchers will compare four groups to evaluate the independent and combined effects of structured exercise training and a structured fruit and vegetable dietary program: * Standard Care Group: Receives standard multidisciplinary obesity care. * Exercise Group: Receives standard care plus a 12-week supervised, structured multicomponent exercise program, weekly exercise counseling, and continuous physical activity monitoring using a tracker. * Dietary Group: Receives standard care plus a 12-week fruit and vegetable enrichment program involving daily smoothie consumption designed to provide one cup of fruit and one cup of vegetables per day, using frozen smoothie ingredient packages delivered to participants' homes, and weekly dietary coaching. * Combined Exercise and Dietary Group: Receives standard care plus both the structured exercise and fruit and vegetable dietary programs. During the 12-week study, participants will complete assessments at baseline, week 6, and week 12. Some procedures may be completed at home or split across more than one day. Assessments may include: * Providing blood, urine, and stool samples. * Completing questionnaires about health, sleep, diet, physical activity, mood, and other health behaviors. * Undergoing body-composition scans to measure fat, lean, and bone mass. * Completing blood-vessel function, liver-fat, and skin-carotenoid assessments. * Completing continuous glucose monitoring. * Assessing resting energy expenditure. * Completing fitness and muscle-strength tests. * Completing a standardized meal-based metabolic assessment. * Completing 3-day dietary records. * Wearing activity and sleep monitors to assess physical activity and sleep patterns.

Detailed Description

The Level Up! study has a 12-week intervention period. Assessments are planned at baseline, week 6, and week 12 at the Arkansas Children's Nutrition Center (ACNC). Some procedures may be completed at home or split across more than one day. On-site assessments may last up to six hours, and some procedures require participants to fast, with water permitted after midnight. Trained personnel will conduct assessments according to standardized procedures. Assessments include: * Medical history, vital signs, and anthropometric measurements, including height, body mass, sitting height, and body circumferences. * Whole-body and regional body composition measured by dual-energy X-ray absorptiometry (DXA), including fat, lean, and bone mass. * Fasting venous blood, spot and 24-hour urine, and stool sample collection. * Continuous glucose monitoring using an interstitial glucose sensor. * Brachial artery flow-mediated dilation assessed by ultrasound. * Liver steatosis and stiffness assessed by FibroScan, and skin carotenoid levels measured using the Veggie Meter. * Resting metabolic rate measured by indirect calorimetry. * Cardiorespiratory fitness assessed by cardiopulmonary exercise testing (CPET) on a cycle ergometer, with breath-by-breath gas-exchange measurement to determine peak oxygen uptake. * Knee extensor and flexor strength assessed by isokinetic dynamometry, and handgrip strength measured using a digital handheld dynamometer. * Physical activity and sleep monitored using accelerometers worn at the wrist and hip, and dietary intake assessed using three-day food records. * Substrate utilization assessed during a mixed-meal tolerance test (MMTT) using indirect calorimetry. * Questionnaires assessing sleep, anxiety and depressive symptoms, substance use, physical activity enjoyment, socioeconomic background, and pubertal status.

Eligibility Criteria

Interventions