•Prior behavior and inherited and acquired characteristics influence beliefs, affect, and enactment of health-promoting behavior.•Persons commit to engaging in behaviors from which they anticipate deriving personally valued benefits.•Perceived barriers can constrain commitment to action, a mediator of behavior as well as actual behavior.•Perceived competence or self-efficacy to execute a given behavior increases the likelihood of commitment to action and actual performance of the behavior.•Greater perceived self-efficacy results in fewer perceived barriers to a specific health behavior.