Participant behaviours during a web-based diet history interview: the influence of food type selection on behaviour
Social desirability bias in food type selection may influence patient behaviour during diet history interviews; however, face to face diet history interviews do not allow for participant behaviours to be captured. To determine whether a relationship exists between the foods selected by the participant and observed behaviours, video data was analysed for n = 11 adult volunteers with type 2 diabetes mellitus using an automated diet history website. Participant log files showing time taken and item selection were downloaded from the website. Behaviours from the videos and food item selections from the log files were grouped, and matched for time of occurrence. The frequency and proportion of behaviours per food group were calculated. Trends between food group and behaviour group were determined using weighted chi-square analyses. Sixteen behaviour groups were constructed from 155 behaviours and 11 food groups were formed. Adjusted for voice alteration; the most commonly observed behaviour was non-computer interaction in the savoury sauces (14.0%) group; self touching of the face in the sugary foods (20.2%), and fats and oils (16.9%) groups; shifting in the chair in the takeaway food group (20.2%); and head movement (21.6%) in the alcoholic beverages group. Self-touching of the face, head movement, postural movement, and movement in chair were observed significantly more often than other behaviours across all food groups. Food type appears to influence behaviour during diet history interviews. This may have implications for the types of questions asked by dietitians during face to face diet history interviews.