the behavior, the subjective norm, and the perceived behavioral control lead to the formation of a behavioral intention. In particular, perceived behavioral control is presumed not only to affect actual behavior directly, but also to affect it indirectly through behavioral intention. As a general rule, when (a) the individual has a favorable attitude toward a behavior, (b) the attitude is aligned with the relevant norms, and (c) the individual perceives that s/he has a high level of behavioral control, a strong intention to perform the behavior in question is expected. Finally, given a sufficient degree of actual control over the behavior, the individual is expected to carry out his or her intentions when the opportunity arises. Formula In a simple form, behavioral intention for the theory of planned behavior can be expressed as the following mathematical function: The three factors being proportional to their underlying beliefs: To the extent that it is an accurate reflection of actual behavioral control, perceived behavioral control can, together with intention, be used to predict behavior. Applications of the theory The theory of planned behavior has been applied to a number research areas including health-related behaviors, environmental psychology, and voting behavior. Health-related behaviors Several studies found that, compared to TRA, TPB better predicts health-related behavioral intention. TPB has improved the predictability of intention with regard to several health-related behaviors, including condom use, choice of leisure activities, exercise, and diet. In this research, attitudes and intentions tend to be mediated by goals and needs. For example, an individual may be guided by the goal of losing 5 kg of weight in 60 days; a positive attitude and intention towards dieting would be important. However, if a need is taken into account, such as a need for a partner in an individual's effort to lose weight and the person is unable to find such a partner, the individual is not likely to lose weight. TPB can also be applied to the area of nutrition-related interventions. In a study by Sweitzer et al., TPB-related behavioral constructs guided the development of intervention strategies. TPB was applied in such a way as to encourage parents to include more fruit, vegetables and whole grains in the lunches they packed for their preschool children. Knowledge/behavioral control, self-efficacy/perceived behavioral control, subjective norms, and intentions were assessed. The researchers observed in the TPB-oriented intervention a significant increase in vegetables and whole grains in the