Exploring fast food consumption behaviours and social influence.

There has been an increase in the consumption of convenience-style foods. This change has occurred concurrently with a global rise in obesity rates which has led to some researchers blaming the increased consumption of ‘big brand’ fast foods (such as McDonald’s) for expanding waistlines. Nutritional profiling in the initial study showed that the energy provided in a typical fast food meal seemed ‘appropriate’ in terms of a general daily intake but that increased meal sizes, poor ordering decisions and choice of fast food restaurant could influence energy balance and long-term health outcomes. Even though fast foods are occupying a larger part of the diet, limited previous research has explored how social influences (including modelling, social norms and social facilitation) may increase the intake of fast foods. Therefore the aim of this dissertation was to explore environmental, social and demographic influences on the amount of fast food consumed at a single eating occasion. The Fast Food Survey (FFS) was developed and administered to two samples to collect information – including the item/s eaten and any social, environmental or demographic influences that surrounded the consumption – on participants’ most recent visit to one of the large fast food chains in Australia. Results from an initial sample (n=116) revealed both the effectiveness of the program that delivered the FFS and support for the hypothesis that environmental and social factors could influence the amount of fast food consumed. A second study using the FFS aimed to test and develop an existing model of social facilitation (originally developed using ‘general’ eating behaviours) in the specific context of fast food consumption. Accordingly, a larger sample (n=407) was recruited via the Internet. Following path analysis, there was support for the time-extension hypothesis in the current data; eating with other people predicted the time spent eating which subsequently predicted energy consumption from fast food items. Beyond the simple effects of time-extension, further modelling showed that environmental factors, including reasons, for consumption could be associated with increased fast food intake. Analysis of data from the second FFS study showed that men and women were influenced differently by their eating environment – there was a negative direct effect of other people on women’s energy intake from fast food items. The theory of minimal eating suggests that gender roles may alter eating behaviours and offers some explanation for this result. An observational study was conducted in McDonald’s to assess how the presence of male and female company could influence fast food intake in both sexes. A comparison of energy intake by participant sex, group size and the sex composition of the group revealed support for minimal eating norms – men eating with other men ate the most food, while women eating with men ate the least food. Overall, the chapters presented in this dissertation show that, in a fast food consumption context, multiple social influences occur. Therefore, despite changes in the types of food being consumed, the mechanisms altering eating behaviours may be relatively stable. Given the potential association between weight gain and the consumption of fast foods, understanding these influences is a first step toward future intervention.Thesis (Ph.D.) -- University of Adelaide, School of Psychology, 201