Childhood obesity is becoming a challenging issue in China, and parents may playa key role in the development of adolescent obesity. However, the relationships between certain parent-related factors and the development of adolescent obesity are rarely reported in China. Therefore, this study aims to investigate the relationship among Chinese parents' perception of their children's weight, parenting behaviors, parenting style, and adolescents' weight status. Two studies were performed to achieve this purpose. / Key words: adolescent obesity, parenting behaviors, parenting styles / The first study (Chapter 3) examines the validity and reliability of the questionnaires for adolescents and parents; the questionnaires are intended to measure parenting behaviors, parents' perception of their children's weight, and parenting styles in the Chinese context. Several steps were performed. First, the questionnaires were selected based on their validity and reliability, as well as their applicability to the Chinese adolescent and parenting context. Second, the questionnaires were translated into Chinese using a cross-cultural translation technique. Third, five experts were invited to evaluate the content validity and feasibility of the questionnaires for application in the Chinese population. Fourth, 15 pairs of adolescents and their parents were invited to attend a short interview after completing the experimental version of the questionnaires. They were asked to share comments on the readability and cultural relevance of the questionnaire. The questionnaires were then revised according to their feedback. Fifth, 127 pairs of adolescents (10-15 years old) and their parents (Ganzhou: 62 pairs, Shantou: 65 pairs) were recruited to examine the retest reliability and internal consistency of the questionnaires. Sixth, the data collected in the main survey were used to examine construct validity. The result showed that 10 items were excluded because of poor content validity or low intraclass correlation coefficient (<0.7). The internal consistencies of the subscales (ranging from 0.61 to 0.81) were found to be acceptable (Cronbach's alpha >0.6). The goodness-of-fit statistics (RMSEA, CFI, and NNFI) also indicated acceptable fit for the theory models. The results suggest that the validity and reliability of the questionnaires are acceptable, and the questionnaires are applicable to Chinese adolescents and parents in Southern China. / The second study (Chapters 4,5,6) determines the relationships among parenting behaviors, parents' perception of their children's weight, parenting style, and adolescent weight status. A total of 2,143 adolescents and 1,869 parents were recruited from secondary schools in Ganzhou and Shantou in China. The adolescents' weights and heights were measured by trained testers. The dietary habits and physical activity level of the adolescents, as well as parenting behaviors, parenting styles, parents' perception of their children's weight, and demographic information were collected through questionnaires issued to the adolescents and parents validated in Study 1. Several parenting behaviors, including "pressure to eat" and "diet and PA monitoring," were found to be significantly related to adolescents' age and gender-specific BMI Z score (Z-BMI), although the correlation coefficients were low (r ranged from -0.23 to 0.09, p (r ranged from -0.23 to 0.09, p<0.01). The results of the hierarchical multiple regression revealed that "pressure to eat" and "diet and PA monitoring" were the predictors of adolescent Z-BMI. The results of Kappa statistics showed that only a slight agreement exists between parental perception of their children's weights and the adolescents' actual weights (Kappa=0.221, p<0.01). A significant difference in parenting behaviors was found between parents with correct and incorrect perceptions of their children's weight. Compared with the reference authoritative parenting style, the odds of acquiring unhealthy dietary habits were significantly higher for children with authoritarian (Father: OR=1.67, 95%CI: 1.29-2.16; Mother: OR=1.72, 95%CI: 1.31-2.26) and neglectful (Father: OR=2.17, 95%CI: 1.66-2.82; Mother: OR=2.29, 95%CI: 1.76-3.00) parents. The odds of being physically inactive for children with neglectful parents were almost twice than that for children with authoritative parents (Father: OR=2.05, 95%CI: 1.37-3.06; Mother: OR=1.77, 95%CI: 1.18-2.67). Significant differences were found in the parenting behaviors of parents with four different parenting styles. However, no association was found between parenting style and adolescent weight. The data of this study suggest that parenting behaviors are weakly but significantly associated with the development of adolescent obesity. Misclassifications of children's weight status were prevalent among Chinese parents. Parental perceptions of their children's weights were associated with some parenting behaviors related to children's weight development. The adolescents' dietary habits, physical activity, and some parenting behaviors were associated with parenting style. However, there was no direct association between parenting style and adolescent weight. / Wen, Xu. / Adviser: Stanley Sai-Chuen Hui. / Source: Dissertation Abstracts International, Volume: 73-03, Section: A, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 130-163). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

非自殺性自傷行為（以下簡稱自傷行為）在青少年中是一種常見的但卻令研究者和心理治療師感到困惑的行為。青少年為何會自傷是研究的熱點，但研究者們對該問題仍然沒有獲得確實性的結論。為回答這一問題，本論文提出了一個關於自傷行為發展的整合性模型，其中包括自傷行為的三類風險因子：易感因子，特別誘發因子和保持因子。本研究的第一部分通過一個3期的追蹤研究來測試該模型。為了更詳細的瞭解青少年的自傷行為，本論文還進行了第二部分的訪談研究。 / 在本研究的第一部分中，3,600名青少年（56.6%為女性）完成了關於自傷行為和其他與自傷相關因素的自我報告問卷，問卷分三次進行，每次間隔半年。結果表明自傷行為主要用於情緒調節。情緒反應性，不穩定的自我感和人際關係是自傷作為情緒調節工具的易感因素。行為衝動性，自我批評和同伴影響會特別誘發青少年的自傷行為。另外，負面情緒/想法和行為衝動性令青少年持續自傷。 / 在本研究的第二部分中，42名有反復性自傷行為的青少年參與了結構性訪談。參加者同樣將情緒調節作為自傷的最主要原因。負面情緒通常出現在自傷前和自傷過程中，正面情緒和自我覺知的負面情緒通常出現在自傷後。自傷後負面情緒顯著下降表明自傷成功完成了情緒調節作用。自傷後，青少年傾向于尋求朋友的幫助。 / 這些發現有助我們增強對青少年自傷行為發展的理解，也對診斷和治療自傷行為提供了重要的啟示。 / Nonsuicidal self-injury (NSSI) is a common and perplexing behavior among adolescents. The question why adolescents engage in this self-destructive behavior is a hotly-studied topic, yet conclusive answers to this question have not been reached. To address this question, this dissertation proposed an integrative model of the development of NSSI. In this model, three types of risk factors: predisposing factors, specific vulnerability factors and maintaining factors for NSSI were examined. In Part 1 of this dissertation, a 3-wave longitudinal design was used to test this model. To understand adolescents’ experience of NSSI in more details, Part 2 of this dissertation reported findings from structured interviews conducted with selected repetitive self-injurers. / In Part 1 of this dissertation, 3,600 adolescents (56.6% females) completed self-report questionnaires assessing NSSI and a comprehensive set of NSSI correlates for three waves over one and a half years. Results showed that NSSI mostly served the emotion regulation function. Emotion over-reactivity, unstable sense of self and relationship problems predisposed adolescents to adopt NSSI as an emotion regulation strategy. Behavioral impulsivity, self-criticism and peer influence served as specific vulnerability factors for NSSI. Unwanted emotions/thoughts and behavioral impulsivity also contributed to the maintenance of NSSI. / In Part 2 of this dissertation, 42 repetitive self-injurers completed individual structured interviews assessing their lived experience of NSSI. Participants again rated emotion regulation to be their primary reason for engaging in NSSI. Negative affects often occurred before and during NSSI, while positive and self-conscious negative affects often followed after NSSI. Negative affects significantly decreased after NSSI, suggesting that NSSI successfully accomplished the emotion regulation function. After NSSI, adolescent self-injurers tended to turn to their friends for help. / Findings of this dissertation enhanced our understanding of the development of NSSI among community adolescents. Conceptual and clinical implications of these findings were discussed. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / You, Jianing. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 128-136). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.i / Acknowledge --- p.iv / List of Tables --- p.vi / List of Figures --- p.viii / Overview --- p.1 / Chapter Part 1: --- Tracking the Developmental Trajectories of Nonsuicidal Self-injury among Chinese Adolescents --- p.3 / Introduction --- p.3 / Method --- p.19 / Results --- p.31 / Discussion --- p.73 / Chapter Part 2: --- Lived Experience of Nonsuicidal Self-injury Among Chinese Adolescents --- p.87 / Introduction --- p.87 / Method --- p.90 / Results --- p.93 / Discussion --- p.114 / General Discussion --- p.121 / References --- p.128