A broad set of studies have demonstrated socioeconomic discrepancies in morbidity and mortality to exist at every level of the social hierarchy (e.g. Adler et al., 1994). Recently, evidence is emerging which shows a distinct trend towards higher levels of obesity in lower socioeconomic groups (e.g. Shrewsbury and Wardle, 2008; Zaninotto, Head, Stamatakis, Wardle, and Mindell, 2009). The rapidly rising prevalence of obesity, particularly among the disadvantaged, is a crucial issue for an aging population in Europe where obesity is likely to predispose individuals to persistent health conditions, disability, and considerable healthcare costs (Stanton, Revenson, and Tennen, 2007; Müller-Riemenschneider, Reinhold, Berghöfer, and Willich, 2008). This proposal aims to identify key psychosocial and behavioural factors that may explain socioeconomic differences in obesity levels. It then aims to show that it is possible to introduce theory-driven behavioural interventions to vulnerable groups in order to assist in breaking the socioeconomic status – obesity link.