Reactivity to television food commercials in overweight and lean adults: Physiological, cognitive and behavioural responses.

Recent evidence indicates that acute exposure to food advertising increases food intake. However, little research to date has explored the potential mechanisms underpinning this, such as the extent to which food commercials elicit conditioned physiological responses (e.g. increased salivation). The aim of the current study was to examine salivary, cognitive and consumptive responses to televised food commercials in overweight (N=26) and lean (N=29) adult females. Participants attended two laboratory sessions in a counterbalanced order; in one session they viewed a television show with embedded commercials for unhealthy foods, and in the other session they viewed the same show with non-food commercials. In both conditions, following viewing participants were exposed to an in vivo food cue (freshly cooked pizza) which they were then invited to eat ad libitum. Salivation was measured at baseline, during commercial exposure, and during in vivo exposure. Participants also self-reported components of appetite on visual analogue scales and completed a word stem task. Results indicated little evidence of increased salivary reactivity to the food commercials. In both conditions, lean participants showed reliable salivary responses to the in vivo food cue. In contrast, overweight participants only showed increased salivation to the in vivo cue in the food commercials condition. Food commercial exposure did not increase the number of food-related cognitions or amount of food consumed, but did drive a greater increase in desire to eat prior to pizza consumption than exposure to the control commercials. Exposure to food advertising primes eating-related motivations, and while it may not be associated with increased intake or salivation per se, non-food commercials may attenuate subsequent physiological responses to actual food cues in overweight individuals.