In this dissertation, a new construct is introduced as a means for systematically assessing the meanings associated with eating behavior and food choice. There are many determinants of food choice that have been operationalized throughout the health behavior literature. Some factors are instrumental, external, and/or immediate, whereas others are more global, higher-order and distal from the process of food selection and eating. However, the literature still lacks a comprehensive construct for systematically assessing the ways that food is related to people’s larger meaning systems, systems composed of durable and enduring values, goals and beliefs. The Meaning of Food in Life (MFL) project was therefore designed to operationalize the construct of the MFL as well as explore how this, in turn, influences food choice. First we introduce the theoretical basis for systematically operationalizing and investigating the MFL, and then explore its relationship to food choice, moral psychology and wellbeing. We articulate a clear definition of the meaning of food; namely, that for something to constitute a food meaning it must be connected to or embedded in a person’s life-world, in contrast to orientations to food rooted in the proximal and immediate demands of the eating situation. Then, over three separate studies, we developed and validated a questionnaire that assesses the meaning of food in life, and demonstrate the ways that different food meanings are linked with different food-related attitudes, motivations and behaviors. In Study 1, we present the development and validation of an assessment tool for empirically measuring the MFL. In this investigation we operationalize the MFL and generate a 22-item tool for its assessment. The items were tested in an online format in three empirical studies (n = 560), and participants were recruited through MTurk. Exploratory factor analyses and item analysis were conducted to confirm the psychometric characteristics of the item pool. Overall, five distinct domains of food meanings emerged: moral, sacred, health, social, and aesthetic. Each domain of food meaning was significantly associated with different dietary intake outcomes, providing evidence for construct validity. Further, each dimension of food meaning displayed associations with psychologically similar, yet distinct constructs from the literature in a manner concordant with the theoretical specifications of each construct, providing further validity evidence. The associations between the different domains of food meanings and behavioral outcomes suggest that this construct may be an important and clinically relevant aspect of people’s relationship to food that has heretofore lacked systematic investigation. Study 2 evaluated how the five domains of the MFL, namely, moral, sacred, social, aesthetic and health, relate to determinants of healthy eating behavior and a positive relationship to food. We administered a questionnaire to an online sample of 252 American participants. Measures included demographics, the MFL, self-efficacy for eating healthy foods, a positive relationship to food, fruit and vegetable (F&V) stage of change, calorie restriction, and body satisfaction. Data were analyzed using correlation and regression analyses. Results demonstrate that the moral, aesthetic and health domains of the MFL were positively associated with greater self-efficacy for consuming healthy foods (all p < .001), and the moral and health domains were positively associated with greater body satisfaction (both p < .01). All five MFL domains were positively associated with F&V stage of change (all p < .01) and a positive relationship to food (all p < .05, or less), whereas none were associated with calorie restriction. These data suggest that the MFL has clinical health relevance in the form of promoting healthier dietary behavior and a positive relationship to food. The discourse around food has shifted in recent years, fueled by growing concerns over the environment, animal welfare, and public health issues such as obesity. One domain that hasn't yet been considered in terms of its relation to food choice is that of compassion and self-compassion, independent yet related constructs encompassing a concern for the suffering of others or the self, accompanied by a desire to alleviate that suffering. In Study 3, we investigated the associations between compassion, self-compassion, the meaning of food in life, healthy and sustainable eating behavior, and a willingness to pay higher prices to ensure environmental protection and animal welfare. We collected data from 254 subjects via MTurk. Results indicate that compassion was significantly linked with behavior that entailed reducing the suffering of others, demonstrated by the negative associations between compassion and meat intake (p < .05), and the positive links between compassion and limiting intake of fast food (p < .05) as well as a willingness to pay higher prices to ensure animal welfare (p < .001). Self-compassion was positively associated with making healthier choices for the individual, indicated by significant associations with increased vegetable intake (p < .01), and with limiting intake of candy, soda and processed foods (all p < .05). For many of the dietary outcomes, both self-compassion and compassion made unique and significant contributions, suggesting their effects may be additive and potentially influence dietary behavior through different mechanisms. This preliminary investigation should pave the way for future investigations into these relationships and their potential applications. Overall, this research project generated the theoretical and empirical foundations for operationalizing the MFL as a determinant of food choice. We came up with a definition for the meaning of food, namely, that for something to constitute a food meaning it must be embedded in a person’s larger life-world, rather than be limited to the immediate demands of the eating situation. While there already exist several measures that measure motivations for eating across the board, as well as measures that measure the proximal factors which influence eating, to our knowledge, this is the first study to exclusively focus on and operationalize the distal factors which influence food choice – the factors which, by definition, are non-immediate, and which are connected to non-food aspects of life. These non-food related aspects of eating life, as our empirical data have shown, include moral and value-based orientations to food, the social and cultural importance of food and eating, the sacred or spiritual connections between people’s food choice and belief systems, the meaningfulness of nourishing one’s body in a healthy fashion, and the aesthetic dimensions of food, whereby food is seen to be an arena for creativity and artistic expression. Our repeated empirical investigations confirmed that the five domains of moral, social, sacred, health and aesthetic consistently emerge as distinct factors that influence food choice.

For chronic dieters, modern food environments make it very difficult to always behave inline with health goals. Approximately 45 million Americans report never fully being off a diet because they fail to reach their weight loss goals. These individuals are colloquially known as chronic dieters but in the food behavior and literature, these people are known as Restrained Eaters. Restrained Eaters are known for the vacillation between food restraint and disinhibition. Past research has demonstrated that one way to keep Restrained Eaters from reach disinhibition is to prevent or weaken their involuntary physical and cognitive responses to external food cues. In a series of three lab studies, this dissertation tests two novel approaches to influencing the behavior of Restrained Eaters when faced with a hedonic food item. The focus of Study 1 is on using Query Theory to test whether there is an effect of endowment on decision and whether thoughts predict decision. We found a significant effect of endowment on the decision of Restrained and Unrestrained Eaters. Study 2 also uses Query Theory but reverse the natural order in which participants generated thoughts and whether that had an effect on decision. In Study 2, we found changing the natural order of thoughts can reverse the effect of endowment. Studies 3 and 4 reanalyze the data from Studies 1 and 2 using Regulatory Focus Theory. In this reanalysis, we found thoughts coded using regulatory focus also predicted behavior. We use the results from this reanalysis to justify Study 5, which is a test of regulatory focus inductions on decision. We found no significant effect of regulatory focus inductions on the decision of Restrained or Unrestrained Eaters. This research aims to develop interventions that will help Restrained Eaters make decisions that are not overshadowed by external cues or instant gratification, giving them a better chance to reach a sought out goal.

Learning processes play a major role in controlling intake of food. Through repeated experiences an animal acquires the ability to predict the postingestive effects of a particular food (i.e., of its nutrients and energy) from its sensory characteristics. What is unclear from the literature, however, is whether an animal can anticipate the duration of subsequent food deprivation from predictive sensory qualities of a food, and hence increase the amount eaten of that cueing food. Therefore, the aim of this work was to investigate the characteristics of this under-researched type of learning, i.e., anticipatory eating, using laboratory rats trained on two lengths of fasting (short: 2-3 h, long: 8-10 h). The main findings were as follows. 1) Anticipatory eating is learnt when a choice is given between protein- and carbohydrate-rich foods as well as on a single balanced test food. 2) The learnt extra intake of food is instrumental to preventing the return of hunger, removal of which negative reinforcement extinguishes the response. 3) The resulting return of hunger induces re-learning of anticipatory eating. 4) During the training sessions, learning of anticipatory eating competes with classical conditioning of sensory preference. Conditioning of preference is likely to be stronger with the shorter than with the longer length of fasting. Therefore, the difference between intakes before the long and the short fast at each trial is the summed result of these two mechanisms of acquired increase in intake. While preference conditioning usually reaches a maximum rapidly, depletion-avoidance increases for as long as has been tested, with interruptions of rapid self-extinction and re-learning, This self-extinction contributes to the homeostatic character of this learning. 5) High-fat maintenance diet attenuates the learning of anticipatory eating. Overall, the findings provided robust evidence that eating in rats can be controlled by instrumental learning reinforced by hunger. Accordingly, the design of an experiment on such instrumental control of eating in human subjects is proposed to conclude this thesis.

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See abstract in the front page: / Thesis (PhD (Psychology))--University of Pretoria, 2007. / Psychology / unrestricted

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The effect of portion size on food intake is a well-documented phenomenon: when served larger portions, individuals significantly increase their food intake. Insofar authors have limited their research on presenting the potential outcomes, while identifying several conditions favorable to this phenomenon. Indeed, the mechanisms of this effect are poorly understood and no research has insofar provided conclusive evidence regarding the underlying mechanism that could help explain the portion size effect. The first part of this dissertation aimed to fill this gap. We argue that the anchoring and adjustment heuristic accounts for most of the favoring conditions evidenced in earlier research and present it as a possible mechanism underlying the portion size effect. In this view, the portion size served is used as an anchor whereas other influences (i.e. economical, metabolic, regulatory, physiological, sensory, social and environmental) may further contribute to adjust total amount of food consumed. Moreover, we argue that prevention strategies based on this decision making literature may be similarly effective to limit excess food intake from enlarged portions. <p><p>The second and third chapter of this dissertation focus on two other factors related to the portion size of foods, namely the container size and the structure of the portion (i.e. food item size). The discussion of this dissertation reviews the facilitating conditions put forward previously to understand the portion size effect, as well as those reinforcing this effect, and how they may be integrated in an anchoring and adjustment perspective of eating. Finally, it aims to provide a food intake model that may accommodate for most environmental influences, with a special focus on the three influences mentioned above. / Doctorat en Sciences Psychologiques et de l'éducation / info:eu-repo/semantics/nonPublished