目的：瞭解青少年超時看電視之發展軌跡的類型及特性，並進一步探討發展軌跡類型與身體質量指數的關係。方法：使用「兒童及青少年行為之長期發展研究」計畫，針對第二世代樣本（2001年就讀小學四年級），共1382名男生和1302名女生，自2001年至2008年所收集的追蹤資料，進行次級資料分析。研究變項包括樣本自陳之看電視行為、身高體重、以及個人背景與行為因素的相關變項。以發展軌跡模型確認樣本超時看電視的發展軌跡類型，並以廣義線性模式分析其與身體質量指數的關係。結果：男生和女生看電視超時之發展軌跡，各確認有「低－低」、「高－低」、「低－高」、「高－高」四種類型。在控制相關因素的影響後發現，「高－高」組的男生，其BMI的平均值顯著地比「低－低」組高1.07；而「高－高」組的女生，其BMI的平均值顯著地比「高－低」組高0.69。結論：本研究證實，在控制相關因素的影響後，長期持續超時看電視對青少年身體質量指數有顯著效果。

Objectives. To identify the trajectory patterns of excessive television viewing among adolescents in Taiwan and to understand the characteristics of each pattern and its effect on BMI.Methods. A panel sample of 1382 boys and 1304 girls (4th graders in 2001) from The Child and Adolescent Behaviors in Long-term Evolution (CABLE) Study were used. Self-reported television viewing behavior, height, weight, and other covariates were collected every year from 2001 to 2008. Trajectory patterns of excessive television viewing were identified by group-based trajectory modeling, and the effects on BMI were evaluated by GEE.Results. Four patterns of excessive television viewing in both boys and girls were identified: 'Low-Low', 'High-Low', 'Low-High', and 'High-High'. After adjusting for demographic characteristics, obesity-related behaviors, parents' BMI, age, and pubertal development, the effect of trajectory patterns of excessive television viewing on BMI remained significant. Boys in the 'High-High' group had a significantly higher mean BMI (β=1.07) than those in the 'Low-Low' group. Girls in the 'High-High' group had a significantly higher mean BMI than that of girls in the 'High-Low' group (β=0.69).Conclusion. Long-term excessive television viewing has independent significant effect on adolescent BMI.