Obesity is becoming ever more prevalent across the globe, to the detriment of both individual and societal welfare. It is recognised to be a multifactorial issue, with television viewing and food advertisement exposure having become implied as substantial causes. Within the past decade or so, digital media have overtaken television as the predominant audiovisual medium and allow for much more sophisticated advertising. Moreover, on digital media, advertisements may not even be the primary source of exposure to food. It is an omnipresent subject on social photography and video streaming websites, many of which invite interactive user engagement. How, then, does all this food content affect eating behaviour?

Ample theoretical and empirical evidence renders it a fact that exposure to food content can increase appetite. However, relatively novel findings point at mental simulation and imagery as possible mechanisms and applications by which food content may be used also to decrease appetite. The purpose of this PhD project, therefore, was to understand how engagement with digital food content influences eating behaviour in general, and to explore so-called “digital satiation” effects in particular. Towards this purpose, the project drew majorly on the conceptions of grounded cognition and habituation theory.

An initial literature review paper mapped out the digital food photography engagement activities and their relationship with eating behaviour. Viewing food photography content mostly increases appetite. Taking food photographs for private use can beneficially heighten the attention towards the current meal, thereby amplifying meal enjoyment and memory encoding, for a potentially improved long-term food intake regulation. However, taking food photographs to share in public invites social comparison, heightening self-consciousness, which, in turn, decreases the attention towards the meal and reduces its enjoyment.

Three subsequent experimental papers investigated the effects of repeated visual food content exposure and mental imagery of consumption on appetite and sensory-specific satiety. Consistent with predictions, imagined consumption of sweet or savoury food resulted in increases in sensory-specific appetite after three repetitions and a return to at least baseline after thirty. The satiation after the imagined consumption of sweet food also tended to transfer more to the appetite for savoury food than vice versa. Contrary to predictions, however, neither visual nor flavour variety of stimuli affected the appetite response. Lastly, imagined consumption was significantly less satiating than actual consumption.

In addition, an ongoing study currently investigates the effects of passively viewing sensory-specific food content on food choice, intake, and appetite physiology, including changes in glucose, insulin and ghrelin concentrations in the blood.

Overall, the project demonstrated that repeated mental consumption of exposed food stimuli is effective. However, relatively small effect sizes as well as unclear contextual limits moderate at present the promise of applying mental consumption in practice. Nevertheless, it remains a subject worthy of scientific attention.