Transitioning towards more plant-based diets: sharing expert knowledge through a system lens.

Transitioning towards more plant-based protein diets is essential for public and planetary health. Current research about consumption practices of protein sources provides limited insight in the multidisciplinary nature and interconnectivity of the food environment. This study aimed to collect mental models of review authors by synthesizing both their implicit and explicit system views into an overarching system view. Published reviews were used to select participants and identify variables that explain the protein transition in relation to the food environment. To overcome differences in disciplines and scale levels (e.g. individual, interpersonal, environmental), variables were organized according to the Determinants of Nutrition and Eating Framework. Eight review authors shared their mental models in an interview. Participants were asked to construct a causal loop diagram (CLD), a tool proven valuable in making one's ontology explicit to others. Implicit system views in narrative were converted into CLDs using a coding framework. The overarching system view suggests that a multitude of feedback loops sustain current consumption patterns of protein sources, for example by reinforcement through habit, availability and peer support. Several aspects require further research, such as variable relationships that were subject to disagreement and the lack of reciprocity between the physical and social elements of the food environment. In addition, knowledge gaps were exposed, including long-term behaviour and interaction of multiple variables. As a boundary object, the overarching system view can facilitate the direction of future research. The findings underscore the interconnected nature of many disparate elements within the food environment, stressing the need for holistic methods like systems thinking. These are essential in developing a systemic understanding and facilitating the transition towards more plant-based diets.

Value conflicts in mothers' snack choice for their 2- to 7-year-old children.

Value conflicts appear when people experience struggles, doubts, and feelings of guilt when making food choices. This study aims to provide insight into value conflicts, which mothers may experience while providing snacks to their young children. Mothers are mainly responsible for providing the snacks their young children eat, making it a big responsibility for them as children's dietary behaviour tracks into adulthood. Possible value conflicts Dutch mothers (n = 136) experience while providing snacks to their 2- to 7-year-old children were investigated using food and motivation diaries and semi-structured interviews. Differences between mothers' educational level, first versus not-first child, and the differences in age of the children were taken into account. Results showed that the younger the children, the more value conflicts the mothers experienced. Mothers experienced most value conflicts when they provided snacks perceived as unhealthy. Six main value conflicts are elicited by this study, namely, conflicts between healthy and unhealthy snacks; conflicts between healthy and convenient snacks; conflicts related to providing snacks just before dinner; conflicts related to influence of others; conflicts when the child asks but the mother says "no"; and conflicts related to many unhealthy snacks at parties or visits. The insights gained in this study can be used for interventions to promote a healthier lifestyle, support the design of new snack products, and can give guidance for marketing challenges in global snack markets.

The importance of hormonal circadian rhythms in daily feeding patterns: An illustration with simulated pigs.

The interaction between hormonal circadian rhythms and feeding behaviour is not well understood. This study aimed to deepen our understanding of mechanisms underlying circadian feeding behaviour in animals, using pigs, Sus scrofa, as a case study. Pigs show an alternans feeding pattern, that is, a small peak of feed intake at the beginning of the day and a larger peak at the end of the day. We simulated the feeding behaviour of pigs over a 24h period. The simulation model contained mechanisms that regulate feeding behaviour of animals, including: processing of feed in the gastrointestinal tract, fluctuation in energy balance, circadian rhythms of melatonin and cortisol and motivational decision-making. From the interactions between these various processes, feeding patterns (e.g. feed intake, meal frequency, feeding rate) emerge. These feeding patterns, as well as patterns for the underlying mechanisms (e.g. energy expenditure), fitted empirical data well, indicating that our model contains relevant mechanisms. The circadian rhythms of cortisol and melatonin explained the alternans pattern of feeding in pigs. Additionally, the timing and amplitude of cortisol peaks affected the diurnal and nocturnal peaks in feed intake. Furthermore, our results suggest that circadian rhythms of other hormones, such as leptin and ghrelin, are less important in circadian regulation of feeding behaviour than previously thought. These results are relevant to animal species with a metabolic and endocrine system similar to that of pigs, such as humans. Moreover, the modelling approach to understand feeding behaviour can be applied to other animal species.

ENERGY Pro: Spatially explicit agent-based model on achieving positive energy districts.

This article describes the ENERGY Pro agent-based model using the Overview, Design Concept, and Details + Human Decision-making (ODD+D protocol). The model is empirically explicit and aims to investigate the adoption decisions of homeowners in Amsterdam on different energy-efficient retrofitting (EER) measures. Following the ODD+D protocol, this study uncovers the conceptual framework used for model construction, the spatial microsimulation process of expanding the data, and the model implementation details. The article also describes sensitivity analysis, validation results, and how to use and adapt the model. With this article, the authors aim to make the model replicable and accessible to other researchers and inspire them using the combination of social simulation and spatial microsimulation in studying the energy transition.•The agent-based model is described using the ODD+D protocol.•The combination of simulation methods is used for constructing an empirical model.•The model on energy transition can be adapted for other cities.

Values and value conflicts in snack providing of Dutch, Polish, Indonesian and Italian mothers.

This study investigates which values play a role in the decision of mothers about snacks to offer to their young children with a focus on the value conflicts that might occur. The study explores whether national culture is reflected in mothers' values in snack choice for their young children and the related value conflicts. Semi-structured interviews with 67 mothers of 2-7 years old children divided over 4 national cultures (Dutch, Polish, Indonesian and Italian) were conducted. Questions were asked about their values and value conflicts when providing a snack to their young children. Four key themes could be distinguished to cluster the mentioned values. The health-related key theme includes all values that are associated with the healthiness of the product, the child-related key theme all values that connects to the child, the time-related key theme includes the value convenience and the product-related key theme includes all values that are associated with the product itself. Dutch and Polish mothers mostly valued health of the snack, whereas Indonesian and Italian mothers mostly valued the preference of their child. Data also shows specific prevalence between values and nationalities: convenience was very important for Dutch mothers, valuing organic food was typical for Polish mothers, religion played a role for Indonesian mothers, while Italian mothers placed more value on brand compared to the mothers of other cultures. In all cultures, the value conflicts mentioned were mainly related to health.

How social factors and behavioural strategies affect feeding and social interaction patterns in pigs.

Animals living in groups compete for food resources and face food conflicts. These conflicts are affected by social factors (e.g. competition level) and behavioural strategies (e.g. avoidance). This study aimed to deepen our understanding of the complex interactions between social factors and behavioural strategies affecting feeding and social interaction patterns in animals. We focused on group-housed growing pigs, Sus scrofa, which typically face conflicts around the feeder, and of which patterns in various competitive environments (i.e. pig:feeder ratio) have been documented soundly. An agent-based model was developed to explore how interactions among social factors and behavioural strategies can affect various feeding and social interaction patterns differently under competitive situations. Model results show that pig and diet characteristics interact with group size and affect daily feeding patterns (e.g. feed intake and feeding time) and conflicts around the feeder. The level of competition can cause a turning point in feeding and social interaction patterns. Beyond a certain point of competition, meal-based (e.g. meal frequency) and social interaction patterns (e.g. displacements) are determined mainly by behavioural strategies. The average daily feeding time can be used to predict the group size at which this turning point occurs. Under the model's assumptions, social facilitation was relatively unimportant in the causation of behavioural patterns in pigs. To validate our model, simulated patterns were compared with empirical patterns in conventionally housed pigs. Similarities between empirical and model patterns support the model results. Our model can be used as a tool in further research for studying the effects of social factors and group dynamics on individual variation in feeding and social interaction patterns in pigs, as well as in other animal species.

Unravelling variation in feeding, social interaction and growth patterns among pigs using an agent-based model.

Domesticated pigs, Sus scrofa, vary considerably in feeding, social interaction and growth patterns. This variation originates partly from genetic variation that affects physiological factors and partly from behavioural strategies (avoid or approach) in competitive food resource situations. Currently, it is unknown how variation in physiological factors and in behavioural strategies among animals contributes to variation in feeding, social interaction and growth patterns in animals. The aim of this study was to unravel causation of variation in these patterns among pigs. We used an agent-based model to explore the effects of physiological factors and behavioural strategies in pigs on variation in feeding, social interaction and growth patterns. Model results show that variation in feeding, social interaction and growth patterns are caused partly by chance, such as time effects and coincidence of conflicts. Furthermore, results show that seemingly contradictory empirical findings in literature can be explained by variation in pig characteristics (i.e. growth potential, positive feedback, dominance, and coping style). Growth potential mainly affected feeding and growth patterns, whereas positive feedback, dominance and coping style affected feeding patterns, social interaction patterns, as well as growth patterns. Variation in behavioural strategies among pigs can reduce aggression at group level, but also make some pigs more susceptible to social constraints inhibiting them from feeding when they want to, especially low-ranking pigs and pigs with a passive coping style. Variation in feeding patterns, such as feeding rate or meal frequency, can indicate social constraints. Feeding patterns, however, can say something different about social constraints at group versus individual level. A combination of feeding patterns, such as a decreased feed intake, an increased feeding rate, and an increased meal frequency might, therefore, be needed to measure social constraints at individual level.