Although a large body of research has assessed direct genetic links between parent and child weight status, relatively little research has assessed the extent to which parents (particularly parents who are overweight) select environments that promote overweight among their children. Parents provide food environments for their children's early experiences with food and eating. These family eating environments include parents' own eating behaviors and child-feeding practices. Results of the limited research on behavioral mediators of familial patterns of overweight indicate that parents' own eating behaviors and their parenting practices influence the development of children's eating behaviors, mediating familial patterns of overweight. In particular, parents who are overweight, who have problems controlling their own food intake, or who are concerned about their children's risk for overweight may adopt controlling child-feeding practices in an attempt to prevent overweight in their children. Unfortunately, research reveals that these parental control attempts may interact with genetic predispositions to promote the development of problematic eating styles and childhood overweight. Although the authors have argued that behavioral mediators of family resemblances in weight status, such as parents' disinhibited or binge eating and parenting practices are shaped largely by environmental factors, individual differences in these behaviors also have genetic bases. A primary public health goal should be the development of family-based prevention programs for childhood overweight. The findings reviewed here suggest that effective prevention programs must focus on providing anticipatory guidance on parenting to foster patterns of preference and food selection in children more consistent with healthy diets and promote children's ability to self-regulate intake. Guidance for parents should include information on how children develop patterns of food intake in the family context. Practical advice for parents includes how to foster children's preferences for healthy foods and how to promote acceptance of new foods by children. Parents need to understand the costs of coercive feeding practices and be given alternatives to restricting food and pressuring children to eat. Providing parents with easy-to-use information regarding appropriate portion sizes for children is also essential as are suggestions on the timing and frequency of meals and snacks. Especially during early and middle childhood, family environments are the key contents for the development of food preferences, patterns of food intake, eating styles, and the development of activity preferences and patterns that shape children's developing weight status. Designing effective prevention programs will, however, require more complete knowledge than currently available regarding behavioral intermediaries that foster overweight, including the family factors that shape activity patterns, meals taken away from home, the impact of stress on family members' eating styles, food intake, activity patterns, and weight gain. The research presented here provides an example of how ideas regarding the effects of environmental factors and behavioral mediators on childhood overweight can be investigated. Such research requires the development of reliable and valid measures of environmental variables and behaviors. Because childhood overweight is a multifactorial problem, additional research is needed to develop and test theoretic models describing how a wide range of environmental factors and behavioral intermediaries can work in concert with genetic predispositions to promote the development of childhood overweight. The crucial test of these theoretic models will be in preventive interventions.