Key variables and constructs
Individual level: knowledge, beliefs, attitudes, personality traits, past experiences and change processes
Healthy behaviour is the result of perception of disease susceptibility and severity, perception of the benefits of the behaviour required for disease avoidance or management, exposure to stimuli promoting the action, and personal confidence in the capacity to successfully implement the behaviour.
Perceived benefits and barriers
Cues to action
Theory of Reasoned/Planned Action
Behavioural intention determines the performance of a given behaviour through the influence exerted by beliefs, attitudes, subjective norms and perceived control on intention and behaviour itself.
Attitude toward behaviour
Perceived behavioural control
Information Processing Model 
The capacity of the person to understand and react to information and communication sources influences his/her behaviour.
Who provides the information
How information is created, transmitted, received and assimilated
Transtheoretical Model of Stages of Change 
Willingness or intention to change behaviour varies among individuals and within an individual over time. Relapse is a common event and part of the change process.
Stages of change: (1) Precontemplation, (2) Contemplation, (3) Preparation, (4) Action, (5) Maintenance. Change processes: Cognitive and behavioural; Self-efficacy
Adoption of a new behaviour requires a process, consisting of 7 stages or steps, from ignorance of the problem, through the decision to perform the action, to the final change in behaviour.
Stages: (1) No risk awareness; (2) Aware of risk, but considers oneself not susceptible to it;
(3) Decision-making process, which may be: (4) No action; (5) Ready for action; (6) Action; (7) Maintenance
Interpersonal level: role of environment and social support network
Operating Learning Model 
The probability of performing a behaviour is dictated by the history of consequences (environmental changes, stimuli) contingent to its performance. Behaviours should be defined based on the variables that control them: antecedents (stimulus situation prior to behaviour performance) and consequences (change in environment or stimulus situation immediate to behaviour performance).
Antecedent stimuli; Consequences; Reinforcement principle (positive or negative reinforcement); Principle of punishment (positive or negative punishment); Stimulus control; Reinforcing cultural contingencies
Behaviour is dictated by dynamic interaction of personal factors, environmental influences and behaviour: reciprocal determinism.
Outcome and self-efficacy expectations
Behavioural capacity; Reinforcement
Self-regulation models 
Effectiveness in long-term behavioural change depends on the degree of control the individual has on his/her process of change.
Self-management skills; Self-monitoring; Self-evaluation; Self-reinforcement
Interpersonal and social support theories 
Effective interpersonal communication between the provider and patient, taking into account the significance of the environment surrounding the individual, is essential for the change to occur.
Community-based intervention approach 
Community well-being may be promoted by identification of common problems and objectives, resource mobilisation and development and implementation of strategies to reach such collective objectives, including the creation of structures and policies supporting healthy practices and lifestyles.