促进健康的夏季青年就业计划

实验性的：夏季青年就业计划

参与者将在休斯顿大学夏令营担任初级夏令营辅导员，每周工作时间不超过24小时，周一至周四上午8:30至下午3:30（含中午12点-1点午休时间），工作周期为六周，从六月中旬持续至七月底。 参与者将协助高级辅导员开展室内外活动，包括游戏、素质拓展和学业辅导。 每周五上午10点至12点，参与者将参加职业发展研讨会，内容涵盖沟通技巧、团队协作、简历撰写及求职技能等主题。 中午12点至下午2:30期间，本科生工作人员将组织社交活动并提供学业指导。

行为的：夏季青年就业计划

该干预措施旨在夏季期间为青少年提供为期六周的带薪岗位，让他们置身于类似学年期间的、有组织、有规律且由成人监督的环境中。

Change in Age- and Sex-Specific Body Mass Index (BMI)-For-Age Z-Score (zBMI) From Baseline to Week 6

Height and weight will be directly measured by trained staff. Each measurement will be taken twice, and the average will be used for analysis. Body mass index (BMI) will be calculated and expressed as Centers for Disease Control and Prevention (CDC) age- and sex-specific BMI-for-age z-scores (zBMI). The outcome will represent the change in zBMI from baseline to Week 6. A positive change score will indicate an increase (gain) in zBMI from baseline to Week 6, which will be considered a less favorable outcome. A negative change score will indicate a decrease in zBMI, which will be considered a favorable outcome. A change score of 0 will indicate no change in zBMI (maintenance), which will also be considered a favorable outcome for this intervention because preventing excess BMI gain during summer is a primary goal.

Change in Sedentary Behavior From Baseline to Week 6

Sedentary behavior will be measured in minutes per day using a wrist-worn ActiGraph GT3X accelerometer on the non-dominant wrist over 8 consecutive days, including at least 2 valid weekdays and 1 valid weekend day. Activity intensities will be classified using cut points published by Hildebrand et al. The reported outcome will be the change in average daily sedentary behavior (minutes/day) from baseline to Week 6. A positive change score will indicate an increase in sedentary behavior, which will be considered an unfavorable outcome. A negative change score will indicate a decrease in sedentary behavior, which will be considered a favorable outcome. A change score of 0 will indicate no change in sedentary behavior (maintenance).

Change in Moderate-to-Vigorous Physical Activity (MVPA) From Baseline to Week 6

Moderate-to-vigorous physical activity (MVPA) will be measured in minutes per day using a wrist-worn ActiGraph GT3X accelerometer on the non-dominant wrist over 8 consecutive days, including at least 2 valid weekdays and 1 valid weekend day. Activity intensities will be classified using cut points published by Hildebrand et al. The reported outcome will be the change in average daily MVPA (minutes/day) from baseline to Week 6. A positive change score will indicate an increase in MVPA, which will be considered a favorable outcome. A negative change score will indicate a decrease in MVPA, which will be considered an unfavorable outcome. A change score of 0 will indicate no change in MVPA (maintenance), which will also be considered a favorable outcome.

Change in Sleep Duration From Baseline to Week 6

Sleep duration will be measured in minutes per day using a wrist-worn ActiGraph GT3X accelerometer on the non-dominant wrist over 8 consecutive days, including at least 2 valid weekdays and 1 valid weekend day. Sleep duration will be estimated using the heuristic algorithm looking at the distribution of change in Z-Angle (HDCZA). The reported outcome will be the change in average daily sleep duration (minutes/day) from baseline to Week 6. A positive change score will indicate an increase in sleep duration, which will be considered a favorable outcome. A negative change score will indicate a decrease in sleep duration, which will be considered an unfavorable outcome. A change score of 0 will indicate no change in sleep duration (maintenance), which will also be considered a favorable outcome.

Change in Screen Time From Baseline to Week 6

Screen time in hours and minutes (e.g., television, computer, video games, smart phones, tablets) will assessed via self-report during each 8-day behavioral assessment period. Screen time will be calculated as the average daily duration (minutes/day) by summing total reported screen time across completed daily logbooks and dividing by the number of valid diary days within each assessment period. The reported outcome will be the change in average daily screen time (minutes/day) from baseline to Week 6. A positive change score will indicate an increase in screen time, which will be considered an unfavorable outcome. A negative change score will indicate a decrease in screen time, which will be considered a favorable outcome. A change score of 0 will indicate no change in screen time (maintenance), which will also be considered a favorable outcome.

Change in Unhealthy Food Intake From Baseline to Week 6

Dietary intake will be assessed using the NHANES 23-item Dietary Screener Questionnaire. Adolescents will self-report consumption of food and beverage items over the past day. For this outcome, unhealthy food items will include desserts, sugar-sweetened beverages, salty snacks, and fast food items. Responses will be used to estimate daily intake frequency (times/day) of unhealthy food consumption. The reported outcome will be the change in average daily frequency of unhealthy food intake (times/day) from baseline to Week 6. A positive change score will indicate an increase in unhealthy food intake, which will be considered an unfavorable outcome. A negative change score will indicate a decrease in unhealthy food intake, which will be considered a favorable outcome. A change score of 0 will indicate no change in unhealthy food intake (maintenance), which will also be considered a favorable outcome.

Recruitment Capacity (Percentage Meeting Recruitment Goal)

Recruitment capacity is the percentage meeting the recruitment goal.

Retention

Retention will be calculated as the percentage of enrolled participants who complete both baseline and post-intervention assessments for the primary outcome measures.

Fidelity

Fidelity will be assessed through weekly unannounced direct observations using a structured checklist developed by the research team specifically for the intervention. The checklist will assess key components of intervention implementation, including adherence, dose delivered, quality of delivery, and participant engagement. Each item will be rated using either binary scoring (0 = not implemented, 1 = implemented) or a 5-point Likert scale (1 = strongly disagree to 5 = strongly agree), depending on the construct. All domain scores will be standardized and converted to a percentage scale. Each intervention session will be independently rated by two trained researcher, and ratings will be averaged. Session-level fidelity scores will then be averaged across all observation weeks to produce a single fidelity score. The fidelity score will be expressed as a percentage, with higher scores indicating greater fidelity to the intervention protocol and lower scores indicating reduced fidelity.

Attendance

Attendance will be calculated as the average number of days attended across total offered workdays, using employer time sheets.

Acceptability

Acceptability will be assessed using a quantitative satisfaction measure administered to adolescents following intervention participation. Participants will be asked to rate their likelihood of returning as a paid counselor the following summer on a scale ranging from 1 (not at all likely) to 10 (extremely likely). Individual responses will be averaged to generate a single acceptability score. The total score will range from 1 to 10, with higher scores indicating greater acceptability and willingness to participate again, and lower scores indicating lower acceptability. Scores closer to 10 will represent high acceptability, while scores closer to 1 will represent low acceptability of the intervention experience.

Change in Healthy Food Intake From Baseline to Week 6

Dietary intake will be assessed using the NHANES 23-item Dietary Screener Questionnaire. Adolescents will self-report consumption of food and beverage items over the past day. For this outcome, healthy food items will include fruits, vegetables, 100% fruit juice, and milk items. Responses will be used to estimate daily intake frequency (times/day) of healthy food consumption. The reported outcome will be the change in average daily frequency of healthy food intake (times/day) from baseline to Week 6. A positive change score will indicate an increase in healthy food intake, which will be considered a favorable outcome. A negative change score will indicate a decrease in healthy food intake, which will be considered an unfavorable outcome. A change score of 0 will indicate no change in healthy food intake (maintenance), which will also be considered a favorable outcome.