Projekte

Although eating behaviour is influenced by a variety of motives, when aiming to change eating behaviour the focus is often laid on health and weight control motives, supporting a view of food as health. Dietary guidelines based on this view usually consist of complex, normative, and restrictive rules that are difficult to put into practice for lay persons. The present dissertation proposes an alternative approach. It aimed to shift the focus towards a perspective of food as well-being to acknowledge the psychological benefits of eating. The view of food as well-being was further integrated with simple intervention strategies to simplify behaviour change by reducing the complexity of both triggers and the target behaviour itself. Moreover, the present dissertation provides insights into how this alternative approach might be suited to extend the reach and audience of mHealth apps. Accordingly, the present dissertation had two aims. Firstly, it aimed to shed light on underlying motivations and barriers to mHealth app use using an adaptation of the Precaution Adoption Process Model (PAPM). Specifically, Preference for Intuition and Deliberation in Eating Decision-making (E-PID) was included as a psychological transition barrier to inform the development of mobile interventions that target new user groups. The second aim of the present dissertation was to identify and test a simple intervention strategy for facilitating healthy food choices using a simple visual cue. Specifically, a ‘colourful equals healthy’ association was established and tested using data collected in real-life eating situations. In a first step, a behaviour stage model describing the process of nutrition and fitness app adoption was developed based on the PAPM. The model consists of five stages (Stage 1 ‘unengaged’; Stage 2 ‘decided to act’; Stage 3 ‘decided not to act’; Stage 4 ‘acting’; Stage 5 ‘disengaged’). The stage model was tested for nutrition and fitness apps within the fourth measurement point of the longitudinal cohort study Konstanz Life-Study (N = 1,236 participants). Additionally, potential sociodemographic (age, gender, level of education), behavioural (healthy eating style, BMI) and psychological (E-PID) correlates were assessed to examine potential transition barriers. Analysis of the five behaviour adoption stages showed that participants differed in their readiness to adopt mHealth apps. Stage 1 (‘unengaged’) was the most prevalent stage for nutrition apps (52.4%), while 8.1% of participants currently used a nutrition app (stage 4, ‘acting’). Therefore, data indicates that there is great potential to target new user groups for nutrition apps. Age and E-PID emerged as potential transition barriers. Importantly, ‘unengaged’ non-users showed a preference for an intuitive decision-making style, while ‘acting’ users showed a preference for a deliberative decision-making style, indicating that new user groups might be better reached by designing apps that address a more intuitive decision-making style. Finally, the model revealed differences between non-user groups that might contribute to a better understanding of the motivational underpinnings of (not) using mHealth apps. In a second step, the view of food as well-being was integrated with a simple intervention strategy. A ‘colourful equals healthy’ association that was based on meal colour variety as a visual cue for healthy food choice was established and tested. The ‘colourful equals healthy’ association was established in an observational Ecological Momentary Assessment study with 108 participants who recorded their lunch meals for at least four consecutive days using a mobile visual food record. Analysis of intra-individual relationships between perceived meal colour variety and the consumption of seven food groups (fruit, vegetables, grains and starches, protein sources, dairy, fried foods, sugary extras) revealed that an increased perceived meal colour variety was related to an increased consumption of vegetables and a decreased consumption of sugary extras. Notably, the strength of the relationship between perceived meal colour variety and vegetables did not differ between participants, suggesting a universal relationship between perceived meal colour variety and dietary healthiness. Thus, meal colour variety might be used as a simple cue for healthy food choices. To test this assumption, an Ecological Momentary Intervention was conducted with 80 participants who recorded their lunch meals for a period of three weeks. In the second week of the study, participants received a prompt that was tailored to their individual lunch meal times, asking them to eat a colourful lunch meal. After the study period, participants were asked to evaluate the prompt. Again, perceived meal colour variety was positively related to vegetable consumption. Furthermore, it was negatively related to the consumption of sugary extras, fruit and grains and starches. In the second week of the study, participants consumed more vegetables and less dairy than in the baseline week, indicating that the prompt was successful in changing their eating behaviour. Moreover, participants evaluated eating colourful lunch meals as enjoyable and easy to put into practice. Hence, prompting consumers to eat colourfully is a simple yet effective intervention strategy for promoting healthy food choices in daily life. Low nutrition app use rates highlight that eating behaviour interventions are not a ‘one size fits all’ approach and thus, alternative approaches need to be explored. Traditional approaches focus on the food as health perspective, provide normative guidelines, and are often constraining. The present dissertation complements traditional approaches by introducing an alternative approach that highlights the food as well-being perspective, and demonstrating that encouraging approaches can also result in effective eating behaviour interventions. Based on this alternative approach, simple but effective intervention strategies might be developed and subsequently communicated to consumers to promote health and well-being.