Protein transition in a dynamic food environment: An agent-based model to simulate consumption practices at the household level

Background: Since World War II, consumption of animal-based proteins such as meat and dairy has been rising rapidly in Europe. Excessive consumption of animal-based proteins threatens planetary and public health and future food provision Therefore, a transition from predominantly animal-based foods towards more plant-based diets is desirable. Decision-making at the household level is an essential unit of inquiry as food preferences and social relationships interact and determine the resulting choice for either a meat-based or vegetarian meal. A growing body of literature finds evidence for the role of the food environment in shaping food choices, including the decision for either animal- or plant-based foods. Whatever is consumed in the household, depends on the availability of products at food outlets and, vice versa, food outlets respond to consumption practices in families. These reciprocal relationships can be represented as embedded in a complex system. As experimental studies are limited in their possibilities to address the complexities in the food environment all at once, agent-based models (ABMs) are increasingly used to simulate such systems.
Objectives: This research aims to identify the mechanisms that are responsible for the social practice of consuming animal- and plant-based protein foods in relation to assortments of food outlets, by using an agent-based model. In particular, this research will focus on the dynamics of social influence within household and the reciprocal relationship between households and food outlets.
Methods: Two types of agents exist in the model: consumer agents that are part of a household and social network, and food outlet agents. Consumer agents in the model share a meal three times a day. One of the household members will prepare a meal based on the preferences of whom to prepare the meal for, and the available food products in a food outlet store. Consumer agents value harmonious relationships with others. After each meal, the prepared food is evaluated to each household member’s liking: 1) depending on the type of interpersonal relationships, each member will express his (dis-)liking towards the cook; 2) a consumer agent may update his food preference. Interpersonal relationships are modelled using the power-status theory by Theodore Kemper. The food outlet agents aim to maximize profit. They evaluate their sales and may update their assortment based on shifts in demand.
This agent-based model aims to allow researchers and policy-makers to explore the interactions between the household food decision-making and food outlet assortment and investigate for which conditions we can observe emergence (or not) of current consumption practices of protein sources at the population level.