Having a heightened awareness or an attentional bias (AB) to food and physical activity (PA) visual cues may affect health-related behaviours. The aim of this thesis was twofold, firstly to investigate the methods used to measure AB and secondly, to establish whether there were differences in attentional processing of food and PA cues in normal weight (NW) as compared to overweight and obese (OW/OB) individuals. A review of the literature demonstrated that research related to attentional responses to food and PA cues in OW/OB populations is limited and conflicting. Such inconsistent findings may in part be explained by different methodological approaches used to measure AB. A more direct method of assessing visual attention by means of eyetracking technology is therefore warranted. Few studies to date have used eye-tracking to assess AB to food cues and have only addressed potential differences between NW and OW/OB females. It remains unclear whether there are differences in attentional processing of food cues as directly assessed by visual point of gaze between NW and OW/OB males. Furthermore, no studies have investigated weight group differences in visual attention to PA-related stimuli. Therefore within the current thesis, NW and OW/OB males and females were recruited and attentional processing of food and PA images was assessed using both a direct (eye-tracking) and indirect (a visual probe task) measure of attention. Results demonstrated that high energy dense food images appear to capture visual attention more readily than low energy dense food images and also suggested the possibility of an altered visual food cue-associated reward system in OW/OB males. Weight status also appeared to play a role in attentional processing of PA cues with OW/OB women demonstrating reduced visual attention to PA stimuli. These findings suggest that body mass index may play a role in cognitive processing of food and PA-related information, allowing for further understanding of the psychological and environmental factors associated with obesity.