The incidence of overweight conditions among children and adolescents is a growing national concern. Although current literature suggests that parental health behaviors could influence health behaviors of children, studies have not explored the actual predictive relationships of parents' and their children's weight statuses and weight-related behaviors. In addition, current studies have not tested the influence of parental authority, family communication, or demographic characteristics on the relationships. This study first examines factors that contribute to overweight conditions among children and adolescents and the associated costs. Studies of interventions that target children's and adolescents' weight-related health are then reviewed and provide evidence that parental involvement contributes to intervention success. The theory of planned behavior, social cognitive theory, social action theory, and systems theory are discussed and support the notion that parental influences contribute to the development of children's weight-related health behaviors. To test the relationships, 151 young adults and their parents were recruited and completed a series of questionnaires to describe their weight statuses, dietary behaviors, and physical activity behaviors. In addition, the young adult participants completed questionnaires to further describe their parents' parental authorities and their family communication environments during childhood and adolescence. Comparisons of body mass index, average daily energy consumption, average weekly energy expenditure, and physical activity enjoyment of young adult participants and their parents were conducted with correlation analyses and paired-samples t-tests. Further, multiple regression analyses were used to explore the influence of parental authority and family communication, and demographic characteristics were also considered. The empirical results of the current study indicate that, overall, parents' weight statuses and dietary behaviors help predict weight statuses and dietary behaviors of their young adult children. Further, parental authority scales interact with the relationships. At high levels of authoritarian and permissive parental authorities, young adults tend to have weight statuses that are opposite to those of their parents; at high levels of authoritarian parenting, young adults also tend to follow opposite dietary consumption patterns. The findings in this study have implications for professional practice, parenting practices, and the design of intervention activities. Recommendations for future research are provided.