Improving low fruit and vegetable intake in children: Findings from a system dynamics, community group model building study

Abstract

Many children globally do not meet government guidelines for daily fruit and vegetable intake, and in New Zealand, adherence to the vegetable intake recommendation is declining. This study aimed to identify systemic barriers to children meeting fruit and vegetable (FV) guidelines and generate sustainable actions within a local community to improve children's FV intake. A qualitative system dynamics method of community group model building was used. The research team partnered with Healthy Families Waitākere, a Ministry of Health funded prevention initiative, to recruit 17 participants (including students, parents, teachers, community leaders, local retailers and health promoters) from a low-income, ethnically-diverse community in West Auckland, New Zealand. Three group model building workshops were held during which a systems map was created and used to identify actions by considering causal pathways and reinforcing loops in the system. Barriers to children's FV intake identified by participants were the saturation of fast-food outlets in the community and ubiquitous marketing of these products, the high cost of fresh produce compared to fast food, and parents having little time for food preparation plus declining cooking skills and knowledge. Several actions to improve children's FV intake by improving the local food environment were identified, which will be co-designed further and tested by a collaborative group involving community leaders. This project highlights the effectiveness of group model building for engaging a local community in systems change to improve child nutrition, and supplies a blueprint for future qualitative system dynamics research.

Fig 1. Community food system map (causal loop diagram).

A causal loop diagram (CLD) uses arrows to indicate a causal relationship between variables in a system [25]. The CLDs created in this study describe the causal connection between variables that workshop participants deemed to be important, highlighting the feedback processes that determine system behaviour [25]. A blue arrow with a plus symbol shows that the two variables move in the same direction; if the variable at the tail of the arrow increases or decreases, the variable at the head also increases or decreases, respectively. A red arrow with a minus symbol indicates that the two variables move in opposite directions: if the variable at the arrow tail increases, the variable at the head decreases (and vice versa). The causal loops within the CLD illustrate the way in which a chain effect of a cause can be traced through a set of related variables, back to the original cause [25]. All causal loops in this systems map are reinforcing, indicated with an R in the diagram, which means that they perpetuate either a vicious or virtuous cycle [25].