Medical College of Georgia FitKid Project

描述(由申请人提供)： 长期目标：减少儿童肥胖和相关疾病的流行，这在一定程度上是由于年轻人暴露在“肥胖”环境中，这种环境有利于久坐不动的活动(看电视、视频游戏)和高能量零食，而不鼓励中等强度的体力活动(MVPA)。具体目的：检验以下假设：(1)在提供鼓励MVPA和健康零食的“适体”课外环境的学校就读的年轻人，在3年内体脂百分比(%BF)的增加比没有就读此类学校的年轻人少；以及(2)适体环境将导致心血管(CV)健康、心血管疾病风险概况和心理社会特征的有利变化。形成性研究：两所学校将被随机分配到对照和实验条件下进行试点研究，以指导主要试验中使用的技术的改进；试点干预将持续3个月。主要试验设计：在佐治亚州里士满的18所学校，其中约63%是非洲裔美国人，将被随机分配到对照或实验处理；学校(而不是个人)将是随机和分析的单位。在三个等级(第3-5级)开始和结束时进行的测量将包括：双能X光吸收测量仪的%BF；改良的哈佛台阶测试的CV适合性；血压、总胆固醇与高密度脂蛋白胆固醇的比率；人体测量(身高、体重、腰围)；与运动和PA有关的心理社会变量；以及自由生活的PA和饮食。所有学校都将收到有关健康饮食和PA的信息。对照学校的所有三年级学生将被邀请单独参加测试，而实验学校的所有三年级学生将被邀请参加测试和课外活动，每个上学日下午的测试时间为120分钟。在40分钟内，将提供健康小吃和家庭作业帮助。MVPA的80分钟将强调适合发展的游戏和舞蹈形式，在有利于发展运动能力、享受和技能的环境中提供。这些假设将通过处理x时间方差分析来检验，以确定在3年期间，%BF和相关变量的变化在实验组中是否比对照组更有利。潜在的公共卫生价值：如果数据支持干预的有效性，那么可能会鼓励社区培养适合的课后环境，以防止肥胖和相关的健康问题。

DESCRIPTION (provided by applicant): Long-term objective: To reduce the epidemic of child obesity and related disorders, which is partly due to youths being exposed to "obesogenic" environments that favor sedentary activities (TV watching, video games) and energy-dense snacks, while discouraging moderate-vigorous physical activity (MVPA). Specific aims: To test the hypotheses that (1) youths attending schools that provide a "fitogenic" after-school environment that encourages MVPA and healthy snacks will increase less in percent body fat (%BF) over a 3-yr period than youths who do not attend such schools; and (2) the fitogenic environment will lead to favorable changes in cardiovascular (CV) fitness, CV disease risk profile and psychosocial characteristics. Formative research: Two schools will be randomly assigned to control and experimental conditions for a pilot study to guide refinement of techniques to be used in the main trial; the pilot intervention will last for 3-mo. Design of main trial: 18 schools in Richmond County, Georgia, which is ca. 63% African-American, will be randomly assigned to control or experimental treatments; school (rather than individual) will be the unit of randomization and analysis. Measurements taken at the beginning and end of each of three grades (3rd-5th) will include: %BF with dual-energy x-ray absorptiometry; CV fitness with a modified Harvard Step Test; blood pressure, the total cholesterol to high density lipoprotein cholesterol ratio; anthropometry (height, weight, waist circumference); psychosocial variables related to sport and PA; and free-living PA and diet. All schools will receive information about healthy eating and PA. All 3rd graders in the control schools will be invited to participate in the testing alone, while all 3rd graders in the experimental schools will be invited to participate in both the testing and the after-school sessions, which will last 120 min each school-day afternoon. For 40 min, healthy snacks and homework assistance will be provided. The 80 min of MVPA will emphasize developmentally appropriate games and dance forms, offered in a climate conducive to development of sport competence, enjoyment and skills. The hypotheses will be tested with treatments x time analyses of variance to see if the changes in %BF and associated variables over the 3-yr period are more favorable in the experimental than in the control group. Potential public health value: If the data support the effectiveness of the intervention, then communities may be encouraged to foster fitogenic after-school environments to prevent obesity and associated health problems.