Theoretical framework	Definition
1	Information‐Motivation‐Behavioural Skills Theory (Fisher 1994)	This model of behaviour puts forward that change is most likely to occur if individuals have been provided with relevant, effective information, are sufficiently motivated and have social support. Additionally individuals must have the skill to perform the desired behaviour as well as high self efficacy for the task.
2	Theory of Reasoned Action (Fishbein 1975)	This theory assumes that most socially relevant behaviours are under volitional control, that they are the result of choices made by the individual enacting them. Therefore the intention to enact the behaviour is both the immediate determinant and the single best predictor of that behaviour. Intention to perform the behaviour is influenced by attitudes towards the action. This will include the person's positive or negative beliefs and evaluations of the outcome of the behaviour. Intention is also influenced by subjective norms including the perceived expectations of important others such as family, friends and work colleagues. Behavioural intention results in action.
3	Theory of Planned Behaviour (Ajzen 1991)	The theory of planned behaviour is an extension of the theory of reasoned action. This theory, in addition to the constructs of reasoned action, allows for the impact of past behaviour and also for the individual not always being in control of their behaviour. The notion of behavioural control is included in this theory. Knowledge of the relevant skills and experience, emotions, past track record and external circumstances are important. Behavioural control is assumed to have a direct influence of intention.
4	Social Cognitive Theory (Bandura 1986)	A comprehensive theory of behaviour change, social cognitive theory puts forward a multi‐faceted causal structure of motivation and behaviour. It proposes a reciprocal interaction between the individual, the environment and behaviour. Knowledge of health risks, benefits of change social influences and perceived barriers are important components in addition to self influences. Self efficacy is a key component of this theory. This theory proposes that behaviour change can occur if people perceive that they have control over the outcome, that there are few external barriers and people are confident in their ability to enact the behaviour.
5	Control Theory (Glasser 1985)	Control theory is a theory of motivation which states that behaviour is not a response to external stimuli but that it occurs in response to what the individual most wants at that particular time. Glasser puts forward that all behaviour are a reaction to 1 of 5 internal needs, 1. Survival, 2. The need to belong, 3. In pursuit of power and importance, 4. In pursuit of freedom and independence and 5. To have fun.  Interventions guided by this theory stress positive reinforcement and punishment. Developing an environment in which individuals feel safe will reduce negative responses to behaviour change which may be triggered by perceived threats to survival.
6	Operant Conditioning (Skinner 1953)	A behaviourist theory, operant conditioning puts forward that an individual's behaviour is based on reinforcement and incentives. The process describes how behaviours are acquired and maintained. Behaviour is learned, reinforcement and punishment are key constructs, the consequences of a behaviour once preformed will affect the likelihood of that behaviour being enacted again.
7	Social Comparison Theory (Festinger 1954)	Social comparison theory posits that individuals look to external sources in order to check and align their behaviour. These sources may be other people or may be environmental. The comparisons people make between themselves and external sources may affect their emotions, motivation and subsequently their behaviour. Comparisons can be 'upward' or 'downward'. 'Upward' comparisons occur when the comparison behaviour (or behavioural outcome) of the external source is more optimal and 'downward' comparisons occur when the external source is less optimal than the individual making the comparison. Upward comparisons tend to elicit greater motivation for change however if the gap between the comparisons is very large, without additional support, the individual may be discouraged from change (Martin 2010).
8	Social support theories	Social support is a broad concept. Different theories relate to the ways in which social support has been defined. In a review of the literature on social support theories, Hupcey 1998, found there to be 5 categories of theoretical definitions: 1. Type of social support, 2. Recipients perceptions of support, 3. Intentions or behaviours of the providers, 4. Reciprocal support and 5. Social networks. Social support may include emotional support, support with the specific task targeted for change or with overcoming barriers to change as well as support around providing relevant information or tools. The basic premise of theories in this area is that individuals who are supported in the above mentioned ways will be more likely to change their behaviour than individuals who are not.
9	Relapse Prevention Therapy (Marlatt 1998)	This theory stresses the maintenance of behaviour change, identifying potential steps to prevent relapse. Relapse prevention theory states that relapse is most likely to occur if an individual has low self efficacy, insufficient coping skills. Interventions developed around this theory should prepare individuals for setbacks, these components include, 1. Anticipation of high risk situations, 2. Avoidance of these situations, 3. Working on improving coping responses to these situations, 4. Correctly attributing the cause of the setback and 5. Reframing reactions to the setback.
10	Stress Theories (Lazarus 1966)	Stress theory relates to how an individual copes with a situation. Upon being confronted with an outside stressor, the individual first assesses the significance of the stressor, then their perceived ability to cope with the stressor. These appraisals direct behaviour in the given stressful situation.