The radical growth of diet-related non-communicable diseases (NCDs) is associated with the increased consumption of unhealthy food high in saturated fats, sugar and salt, as well as inadequate intake of fruits and vegetables. It is essential to promote healthy eating behaviour to reduce the prevalence of obesity and diet-related NCDs. Conventional public health initiatives tend to be costly and relatively ineffective due to limited coverage and low flexibility. The omnipresent digital technologies in modern society provide a cost-effective alternative, with the ability to offer instant tracking, feedback and customisation.
With the rising interest in applying digital technology to promote healthy eating, it is essential to identify and categorise existing dietary digital interventions and gauge the efficacy of these interventions to provide a holistic view of the current landscape. At the same time, it is also important to encourage technology developments that aim to tackle barely addressed problematic eating behaviour, such as consumers’ behaviours when eating out. An understanding of consumers’ preferences for the application of digital intervention in eatingout situations forms the basis of future consumer-centric digital product development in public food settings. In the future, the increasingly accessible and affordable digital immersive technology has the potential to allow for new ways of eating behaviour change. It enables multisensory immersion in real time, regardless of location restrictions. The instant manipulation of multisensory contextual cues in immersive technology has the potential to modulate flavour perception, which could subsequently drive consumers into healthier diets, without compromising the overall eating experience. Incorporation of immersive technology with the existing dietary digital interventions could further enhance product flexibility, interactivity and effectiveness.
The present thesis aims to explore different digital technologies to promote healthy eating in the present and the future. The objectives are to identify and categorise existing digital interventions in dietary behaviour change (Paper I), investigate consumer preferences towards the use of a digital menu solution in public catering settings (Paper II) and assess the influence of visual-taste congruency on sweetness perception and product liking in immersive environments (Paper III).
Paper I
A systematic review of the literature on existing dietary digital interventions was conducted. From the literature search, four primary dietary digital intervention methods were identified as: a) the use of personal digital assistants (PDA); b) the use of video games; c) the use of mobile phone applications and d) the use of the internet. The efficacy of all the above digital interventions increased when coupled with personalised feedback and counselling. The use of PDAs with customized feedback was shown to have the maximum effects on eating behaviour change. The flexible and sustainable properties of digital interventions have the ability to bring sufficient improvements in individual eating behaviour. However, programme adherence was a significant issue in the included studies. It is necessary to adopt appropriate customisation based on personal preferences and target population characteristics to encourage sustainable behaviour change in the long run.
Paper II
Consumer preferences toward using an innovative digital menu solution in public canteen services were investigated in the U.K., Denmark, Greece and France. Four dimensions of factors influencing consumer preferences were examined: app function and interface; quality and properties of canteen food; provision of canteen information; and food-related ethical issues. The data collected was investigated in both country-specific and collective manners. Consumers in all four countries valued the food quality and properties the most, especially in food safety, sustainability, hygiene and freshness. Consumers’ preferences in the other three dimensions varied from country to country. Food freshness, food sustainability, easiness to use the app, provision of calories and chef recommendation information and global warming/sustainability issues were the top overall influencers with respect to their corresponding dimensions. The findings provide insight into the future design of a digital menu solution, which is adapted to the country and population context to improve informed food choices in public food settings.
Paper III
A study was designed to assess the collective effect of sweet-congruent and incongruent contextual visual cues on the perceived intensity of sweetness and product liking in immersive virtual reality (VR). Three VR environments were created based on existing evidence on tastespecific visual cues (e.g. shape, colour and visual texture) and evaluated through a pilot study. Perceived taste intensity (sweetness, sourness and bitterness), liking (product and environment), perceived visual-taste congruency, comfort, and environment vividness were evaluated by the participants. The perceived sweetness intensity was significantly elevated in the sweetcongruent VR environment versus the other two environments. Perceived intensity of other tastes remained relatively constant in all environments. Visual-taste congruency did not exert influence on product liking and overall liking. The results confirm the significant influence of taste-congruent visual cues on flavour perception. The findings provide insight into the future application of taste-specific VR environments in modulating of flavour perception and subsequent eating behaviour change (e.g. intake of food products with reduced sugar).
In summary, this present thesis identified four main types of existing dietary digital interventions and showed the efficacy could be improved with tailored feedback and counselling. When designing a digital menu solution for public food services, it is important to consider functions and interface that emphasize food quality and properties. Also, the design should be adapted to the country and populational-specific context. Besides existing dietary digital interventions through mobile and computer devices, immersive technologies such as VR have the potential to change eating behaviour via the modulation of flavour perception through contextual cues. The findings and knowledge in this thesis could provide insight into the development and implementation of future digital interventions to promote healthy eating.