Table 2 A priori and emergent themes

· Psychological mechanisms for change related to the TTM and to the proven efficacy of group interactions

· Vicious and virtuous circles of change

· Physiological mechanisms relating to negative impacts of eating as a replacement to smoking and to positive impacts of improved respiratory function on physical activity

· Psychological mechanisms relating to awareness of eating as a replacement to smoking

· Health behaviours as integrated or discrete; sequential or simultaneous