Ward et al. BMC Public Health 2011, 11:431 http://www.biomedcentral.com/1471-2458/11/431 do appreciate the importance of good nutrition and phy- sical activity, their day-to-day practices are likely to be determined by more acute concerns regarding child health and behavior, rather than the more sustained attention and effort necessary to prevent obesity [13]. Given the critical need to educate parents about their role as gatekeepers in the prevention of obesity, it is sur- prising that relatively little empirical attention has been devoted to intervening in families with preschool-age children before unhealthy nutrition and physical activity patterns have been entrenched [14]. Lack of parent intervention models may be due in part to the many challenges associated with this approach. Creating a home environment that supports healthy weight devel- opment is not as simple as providing parents with infor- mation about nutrition and physical activity recommendations. Parents must be convinced to make obesity prevention a priority despite the multiple, often competing demands on their time and resources. The purpose of this manuscript is to describe the program and research design of a parent-focused intervention for healthy weight development in young children called Parenting SOS: Strategies of Success for Raising Strong and Healthy Children. Descriptions will follow the Con- solidated Standards of Reporting Trials (CONSORT) reporting guidelines. Theoretical Underpinnings and Conceptual Model In order to create an intervention for parents of pre- school-age children that promotes healthy weight gain, it was important first to understand the family context and how it influences child weight and weight-related behaviors, as well as how to motivate behavior change in both parents and children. Darling and Steinberg’s Integrative Model of Parenting provides a conceptual model for understanding the family system and how parent variables (values, parenting style, and parenting practices) affect child behavior [15]. This model suggests that parents’ values and goals, related to their child learning specific skills or behaviors (e.g., living up to their academic potential, listening to and obeying rules and instructions, eating healthy and being active) or developing certain character qualities (being confident, resilient, empathetic, balanced), will influence parent practices and style. Parent practices are the specific stra- tegies or behaviors parents use to help their child achieve certain goals; and practices have a direct effect on child outcomes. Style, on the other hand, is thought to moderate the influence that parenting practices have on child behavior. Style affects the parents’ ability to socialize their child and the effectiveness of their parent- ing practices. Ryan and Deci’s Self-Determination Theory provides a framework for understanding motivations, and suggests Page 2 of 9 approaches for building intrinsic motivation to adopt healthier behaviors [16]. This theory suggests that self- motivation can be enhanced via fulfillment of three innate psychological needs - competence, relatedness, and autonomy. Competence can be enhanced through positive feedback, communications, and rewards that are supportive but also challenging. Relatedness, or the need to feel connected with others, can be enhanced by hav- ing behaviors prompted, modeled, or valued by signifi- cant others. Autonomy can be enhanced through providing choices, acknowledging feedings, and offering opportunities for self-direction. These two theoretical models serve as the basis for the current conceptual model for the parenting for healthy weight intervention described below (Figure 1). This model and the resulting program were developed with the belief that general parenting is the gateway activity for parents to develop appropriate parenting skills for their children’s healthy eating and activity patterns. Methods This study uses a randomized control design to test the efficacy of My Parenting SOS, a 35-week intervention for families with preschool-age children, designed to promote parenting practices that lead to healthy eating and activity behaviors in children. All study procedures have been reviewed and approved by the Institutional Review Board at the University of North Carolina at Chapel Hill (IRB Study # 08-0354). An overview of study design is depicted in Figure 2. Study Hypotheses The study’s primary hypothesis is that, by the end of the 35-week intervention, children in the intervention arm will have a lower mean change in percent body fat com- pared to children in the control arm. Secondary hypoth- eses include: that, in comparison to children in the control arm, children in the intervention arm will: (1) improve the quality of their dietary intake, (2) increase their physical activity, and (3) maintain a lower mean percent body fat following a 6-month, no-treatment maintenance period. We also hypothesize that parents in the intervention arm, in comparison to those in the control arm, will: (1) improve the quality of their dietary intake, (2) increase their physical activity, and (3) improve their general parent behaviors (i.e., general par- enting style and practice) as well as domain-specific practices around feeding and activity. In addition, we will examine the mediating effects of parent motivation, general parenting style and practices, and parenting for healthy weight on the impact of the 35-week parenting intervention on child diet and physical activity behaviors and body fat; although due to the exploratory nature of this aim no hypotheses are offered.