The rise in obesity and its co-morbidities has focused the attention of researchers on factors that influence the consumption of a healthy diet. Obesogenic (obesity-promoting) environments are an important area of investigation and a significant opportunity for health interventions. In this research, we identify the home as just such an environment and argue that the dietary gatekeeper within the home has a significant influence on what a family eats and subsequently the health status of family members. We propose a model that relates dietary gatekeeper cognitions and food-related capabilities to food acquisition and transformation practices and subsequent diet outcomes. An online survey was completed by 326 US and 323 Australian dietary gatekeepers to test the relationships in the model. Our results suggest improving dietary gatekeepers’ capabilities, including their cooking confidence and nutritional confidence, and their food acquisition and food transformation practices can have positive health benefits for gatekeepers and their families. Implications for health policymakers and food marketers are presented.