Solving the diet problem: meals as food choice heuristics for behaviour change

The diet problem is the challenge of choosing a healthy and affordable combination of foods to eat. This problem is complex, involving many possible foods, food attributes, contexts, and potential combinations. The current thesis is that people solve the diet problem by using meals as food choice heuristics: quick and efficient solutions to the computationally elaborate diet problem faced daily. The planning and preparation of meals represent a food choice behaviour that is specific, shared with others and context dependent. Meals are a part of cuisine, which itself follows a set of rules or grammar that reflect what is essential, normal or taboo in a diet for an individual. These rules likely reflect culture, geography, history and social status. The parallels between meals and heuristics from behaviour research are discussed, including recent evidence that support the proposal that food choices are made using heuristics. The potential value of focusing on meals for dietary change interventions is also discussed. The current thesis is that interventions that target meals to promote positive dietary behaviour for the individual, society or planet could be more impactful than those that target single nutrients, food groups or holistic diets.