lunches parents prepared for their children. TPB has guided research aimed at preventing weight regain in individuals who had recently experienced a significant weight loss. McConnon et al. (2012) found that perceived need to control weight predicts the behavior needed for weight maintenance. TPB can also help in assessing the behavioral intentions of practitioners who promote specific health behaviors. Chase et al. (2003) studied dietitians' intentions to promote the consumption of whole grain foods. The study team found that the strongest indicator of dietitians' intentions to promote the consumption of whole grain foods was their normative beliefs about diet. However, some dietitians' knowledge was problematic, with only 60% of dietitians being able to correctly identify a whole grain product from a food label. More recent research based on TPB examined college students' intentions to smoke e-cigarettes. Studies found that attitudes toward smoking and social norms significantly predicted college students' behavior, as TPB suggests. Positive attitudes toward smoking and normalizing the behavior were, in part, helped by advertisements on the Internet. With this knowledge, a smoking prevention campaign was started, specifically targeting college students collectively, not just as individuals. The theory of planned behavior model has thus been helpful in understanding health-related behaviors and developing interventions aimed a modifying those behaviors. Environmental psychology Another application of TPB has been in the field of environmental psychology. Generally speaking, actions that are environmentally friendly carry a positive normative belief. That is to say, behaviors that are consistent with environmental sustainability are widely promoted as positive behaviors. However, although there may be a behavioral intention to practice such behaviors, constraints can impede a sense of perceived behavioral control. An example of such a constraint is the belief that one's behavior will not have an impact. There are external constraints as well. For example, if an individual intends to behave in an environmentally responsible way but recycling infrastructure is absent in the individual's community, perceived behavioral control is likely to be low. The application of TPB in these situations helps explain contradictions such as individuals having positive attitudes toward sustainability but engaging in behavior that is antithetical to the idea of sustainability. Other research has found that attitudes toward climate change, perceived behavioral control, and subjective norms are associated with the intention to adopt a pro-environmental behavior. This knowledge can be applied to policy-making aimed at increasing environmentally friendly behavior. Voting behavior TPB has guided