The Inequity Epidemic

Transkript

1 The Inequity Epidemic How rampant discrimination may be spreading obesity among women Catherine Marsal-Cook (SGB040) and Summer Marsal-Cook (SGB043) 17/12/09 Bachelor Degree in Global Nutrition and Health Life Style Coaching and Fitness Management Specialization Supervisor: Hanne Gillett characters

2 Abstract TOPIC: Our work explores the way weight discrimination-induced stress may contribute to the progression of the obesity epidemic. RESEARCH QUESTION: How does weight discrimination contribute to the persistence of obesity among women although they practice dietary restraint? How does overweight affect subjective social status and desirability? AIM and OBJECTIVE: This thesis will focus on the evidence relating psychological stress to overweight, and investigate how weight-based prejudice and discrimination may trigger psychosocial stress that makes weight management particularly challenging for overweight and obese women in our society. METHODS: Within a phenomenological approach, a qualitative research (focus group interview) has been done with overweight and obese women (N=5) of the School for the Home Guard of South Jutland in Denmark. A narrative analysis was undertaken to increase our understanding of women s subjective experience with being overweight and their perception of its effect on their social reality. RESULTS: Our participants experience social stress and negative emotions in response to discrimination and perceived judgment from thinner people. Stress causes an increase in food intake and a shift in food choice toward sugary/fatty food. CONCLUSION: Our female overweight participants seem to be caught in a vicious cycle of stress and weight gain where each perpetuates the other. While further research is needed, our findings encourage us, as life style coaches, to challenge our own beliefs about overweight people. Our research has persuaded us to be critical of weight loss methods, increase our awareness, question our own beliefs, and encourage further research. Key words: stress, psychological stress, weight stigma, bias, weight discrimination, social desirability, social status, BMI and dietary restraint. 2

3 Table of contents: 1. INTRODUCTION REFINING THE RESEARCH QUESTION DELIMITATION DEFINITIONS OF KEY CONCEPTS RESEARCH QUESTION AIM OF THE THESIS METHODOLOGY AND PHILOSOPHY OF SCIENCE LITERATURE SEARCH The selection of our literature Assessment of the literature THEORETICAL FRAMEWORK STRESS AND OBESITY CORRELATION STIGMA OF OBESITY: THE SOCIAL SUBORDINATION OF WOMEN STRESS, EATING BEHAVIOR AND WEIGHT GAIN Physiological function of changes in food choices DIETARY RESTRAINT: QUALITATIVE RESEARCH SAMPLING STUDY DESIGN: ANALYSIS OF THE FOCUS GROUP INTERVIEW OBSERVATIONS NARRATIVE ANALYSIS First category: Eating Behavior and Stress: Second Category: Dietary Restraint Third Category: Weight Discrimination Fourth category: Stress and Coping Strategies Analysis summary DISCUSSION THE VICIOUS CYCLE BETWEEN OBESITY AND STRESS Stress provokes hyperphagia Inside of the vicious cycle THE RELEVANCE FOR OUR PROFESSION CONCLUSION LITERATURE LIST APPENDIX 1: FOCUS GROUP INTERVIEW: APPENDIX 2: FOCUS GROUP INTERVIEW TRANSCRIPTION FIGURES LIST: FIGURE 1:...17 FIGURE 2:

4 1. Introduction Obesity and overweight are increasing all over the world. Overweight has increased by 75% in Denmark since 1987 and today, there are about 1.3 million overweight people (Danish Statistics, 2009). There are serious negative consequences that follow this trend. The cost associated with overweight is tremendous. The cost in human capital to the Danish society was estimated to be 19 billion Danish kroner per year and is projected to reach 24 billion Danish kroner in Overweight brings with it many illnesses, such as heart disease and diabetes, and has received very much attention as a public health concern. Motivation for solutions is high and many resources are being used for research and public strategies. The expense seems unreasonable when the solution seems so simple; energy expenditure must be greater than energy consumption (Melanson & Dwyer, 2004). Overweight is considered aesthetically undesirable in most western countries and is associated with many negative qualities such as laziness and lacking in selfdiscipline (Puhl and Heuer 2008). One may be tempted to consider these beliefs warranted, when the solution to all these problems is Just eat less! Michael Fuento claimed when somebody shows prejudice to an obese person, they are showing prejudice toward overeating and what used to be called laziness. It s a helpful and healthful prejudice for society to have (Julier, 2008, 490). There are, however, some compelling statistical associations in the epidemiological data that make one want to reconsider this attitude and oblige one to dig deeper into the complexity of overweight. For example, obesity is negatively associated with socio-economic status. The SANCO report 2005 estimated that 20% of obesity in men and 40% of obesity in women is attributable to social and economic inequalities. The Eurothine study estimated 26% and 50% in men and women respectively, and the gap is widening (Robertson, Lobstein & Knai, 2007). Also, Epidemiological data show an association between psychological stress and overweight (Tamashiro, 2007), and recent research has begun to reveal the mechanisms connecting stress and overweight. There are other considerations that cast doubt on the helpfulness of negative attitudes toward overweight and obese individuals. Weight discrimination has increased in the United States by 66% over the last ten years (Puhl and Heuer, 4

5 2008). Stigma and discrimination are found in many domains such as employment, media, education, interpersonal relationships, and health care settings (ibid). Why has the dramatic increase in punishment and negativity toward overweight not slowed the growth of the obesity epidemic? Discrimination can also cause considerable harm to individuals. For example, one study showed that psychological distress related to weight-based stigmatization predicts binge eating (Ashmore, 2007). Other studies show that many women are more vulnerable to overeating during stressful periods (Oliver, 2000). In light of this research on stress and overweight, we hypothesize that discrimination may facilitate rather than deter weight gain. This paper will explore the mechanisms involved in stress, appetite and weight gain. Because of the complexity of the body s reaction to stress, a multidisciplinary approach is appropriate. Changes in the action of hormones caused by psychological stress have the power to change us physically, behaviorally and emotionally. These hormones are interdependent, and affect each other in antagonistic, synergistic, additive, or permissive ways (Mason, 1968). Various systems and organs are affected in ways that change appetite, metabolism, and mood and there is still much that is not yet understood (Shwartz, 2007). Our own research aims to better understand what is happening from the woman s point of view. We want to explore how women interpret their social environment and how it influences their emotions and eating behavior with a particular focus on dietary restraint. What is the relationship between the physiological research, the social scientific research, and the intentionality of the agent? We have interviewed five overweight women who would like to lose weight. We asked questions about their experience with stress, discrimination and bias, how it affects eating behavior, and dietary restraint. As lifestyle coaches our goal is to help people be healthier, and weight loss will be a goal for many we will work with. According to a survey from 2005, one out of every four Danish people went on a diet in the last 12 months (Robertson, Lobstein & Knai, 2007). The abundance of commercial weight loss products is prodigious (Melanson & Dwyer, 2004). These diets make promises that lead women to make unfortunate choices that lead to discouragement and further weight gain (ibid). 5

6 Although there are many effective ways to lose weight, very few manage to maintain their desired weight long term. Some evidence shows that there is series of harms connected with the weight-centered paradigm such as dissatisfaction, dieting, disordered eating, discrimination and death (O Hara, 2006, 262). This prompts us to question our role in assisting weight loss and how we can help our clients in the best way. This paper will focus on the evidence relating psychological stress and overweight, and investigate how weight-based prejudice and discrimination may trigger psychosocial stress that makes weight management particularly challenging for overweight and obese women in our society. We will first describe the processes of our research and methods involved in conducting a focus group interview including five overweight women. We will thereafter analyze and discuss our findings in order to gain a better understanding of the way overweight women experience stress and discrimination. 2. Refining the research question 2.1 Delimitation To classify overweight and obesity, it is common to use the Body Mass Index (BMI). It refers to the weight in kilograms divided by the square of the height in meters (kg/m2), with overweight (BMI > ) and obesity (BMI > 30) (WHO, 2009). WHO defines overweight and obesity as excessive fat accumulation to the extent that there is risk for associated negative health consequences. A person with a BMI of 30 or more is generally considered obese and a person with a BMI equal to or more than 25 is considered overweight (ibid). Also, WHO defines being overweight as being in a pre-obese state (BMI from 25 to 29.9). Furthermore, when we use the term overweight, we assume obese persons fall into the same category. Some claim that overweight is a moral weakness. Overweight people are seen as less competent, lazy, unattractive, unmotivated and with low self-discipline (Puhl and Heuer, 2008). One of the paradigms suggests that weight is volitional and under 6

7 the control of each individual. Overweight people are seen as having poor health (O Hara, 2006). Michael Fuento s quote sited in the introduction, claimed it is helpful and healthful for society to have prejudices toward overweight people (Julier, 2008). As future life style coaches, we felt the need to confront this type of conception of obesity and discover the consequences of the pervasive stigma that is widely present. The relationship between stress and obesity will be used as our framework within which we will focus our research. We will explore both the physiological and psychological effects that stress may induce and suggest that stress may harm health in part through unhealthy food choice (Oliver, 2000) and lead some individuals to gain weight. This paper will present qualitative data obtained through a focus group interview. The goal of this interview was to increase the understanding of women s subjective experience of being overweight and their perception of its effect on their social reality. We chose to focus on women because they are seen to be the most vulnerable to weight discrimination (Puhl and Heuer, 2008). Also, women are more likely to be socially punished for overweight than men and women are 16 times more likely to report weight discrimination in employment than men (Ibid). Furthermore women initiate experiencing weight prejudice at lower levels of body weight than men (Puhl, 2009). There is robust evidence showing a negative correlation between obesity and socio-economic status. However some findings independent of initial socio-economic status, suggest that women are to a greater extent pushed downward in their social desirability (Lissner, 1997). This subjective social status will be explored with the phenomenological nature of our research. Limiting the description of social dominance and hierarchy to objective measures of social status would not have been adequate. Subjective status is a strong predictor of ill-health, and that education, occupation and income do not explain this relationship fully for all the health measures examined (Singh, 2003, 1321). Also, psychological aspects of overweight can be just as influential on health as objective measurements. For example, the level of disparity between one s desired and actual body weight has been found to be more predictive of morbidity than the very objective measure of BMI (Muennig, 2008). 7

8 2.2 Definitions of key concepts The main key concepts of our thesis are listed bellow and will refer to definition as: BMI: Body Mass Index, refers to the weight in kilograms divided by the square of the height in meters (kg/m2) (WHO, 2009). Overweight (BMI > ) and obesity (BMI > 30) (WHO, 2009). Dietary restraint refers to: the tendency to consciously limit the type and amount of food ingested in an attempt to either lose weight or prevent weight gain (Wilson, 2003). Stress: Stress was defined in the early 20th century by Hans Selye, later President of the International Institute of Stress, at the University of Montreal. He defined stress in 1936 as: "the non-specific response of the body to any demand for change" (The American Institute of Stress, 2009). Accordingly to this broad definition of stress, we will however refer mainly in this thesis to the definition of psychological stress: stress wherein emotional factors predominate (Pubmed, 2009). Social status will follow an operational definition. We will use social status subjectively as a term independent of economic status but more as the individual s perception of their place in social hierarchy. We will refer it closely to the nominal definition of social desirability: A personality trait rendering the individual acceptable in social or interpersonal relations. It is related to social acceptance, social approval, popularity, social status, leadership qualities, or any quality making him a socially desirable companion (Pubmed, 2009). Weight Stigma will be used as defined by Rebecca Puhl: a negative weightrelated attitudes and beliefs that are manifested by stereotypes, rejection and prejudice towards individuals because they are overweight or obese. She however differentiates discrimination from stigma and negative weight related attitudes and defines it as: unequal and unfair treatment of people because of their weight (Puhl, 2009). Stigma and discrimination will be tightly linked to subjective social status. 8

9 2.3 Research question Considering the relationship between stress and overweight, our research question is the following: How does weight discrimination contribute to the persistence of obesity among women although they practice dietary restraint? How does overweight affect subjective social status and desirability? 2.4 Aim of the thesis As life style coaches, we must expect to often be confronted with overweight and the challenge of weight loss. We are trained to work with individuals and assist them in reaching their goals. Considering the pervasiveness and focus on overweight in our society, weight loss will often be among these goals. We need to be prepared for the reality of the challenges of maintaining weight loss and be aware of barriers people will be faced with. We hope to gain insight into why people have been so unsuccessful and how to increase the chances of success for our clients. The aim of our research is to increase our understanding of the persistence of overweight among women. We will examine and tie together social and physiological consequences of obesity. Our work will explain some of the complexities surrounding obesity that may seem counterintuitive. We present evidence to support the hypothesis that weight discrimination may contribute to, rather than prevent, progression of the epidemic. 3. Methodology and philosophy of science A qualitative approach was used in order to gain understanding of the subjective significance and gather knowledge on stress and dietary restraint and the 9

10 relationship with stigmatization of overweight and obese women (focus group interview transcription: appendix 2). In this perspective, a phenomenological approach is appropriate considering the personal nature of health behavior and the interaction with others (Bryman, 2004). We chose five women with a BMI between 25 and 39, from a group of employees in the School of the Danish Home Guard in Nymindegab for practical reasons. We had been helping them achieve health related goals as a part of our work placement in the spring and fall of 2009 and their profiles were relevant to our thesis problem. We chose questions on the basis of our theoretical framework. Topics included stress and eating, dietary restraint and its effects, weight discrimination and stress management. The qualitative method was conducted in the tradition of interpretivism using the phenomenological tradition. We wanted to gain access to our participants commonsense thinking and therefore to interpret their action from their own understanding of their world and from their experience (Bryman, 2004). This interpretivist approach gives subjective information about our participants. The information gathered from these five women cannot be generalize to a larger sample of overweight women we will use it as a general sense of reference and guidance in approaching empirical instances (ibid, 271). For example, this subjective data can give insight into qualitative research that describes the statistics of diet failure and the physiological measurements associated with stress. In order to be consistent with interpretivism and the phenomenological tradition, we decided to use a narrative analysis to interpret our findings. Narrative analysis focuses on how people tell their story and relate the understanding of their lives and the world around them (Bryman, 2004). It also emphasizes the interaction of the people interviewed. A narrative analysis can be applied to research methods as semi-structure interviewing (ibid), and has become a distinctive strategy in its own right for the analysis of qualitative data (ibid, 415). We will use three models of the narrative analysis: the thematic ( what is said ), structural ( how it is said ) and interactional (interaction between interviewer and interviewees) models (ibid). Also, contrary to the coding approach of analysis, our focus was not to know what happened but how people make sense of what happen (Bryman, 2004). The 10

11 interview is seen as a whole, as we believe that the fragmentation of data occurring with coding would have detracted from the richness of the data collected (ibid). However, we would like to discuss the findings of our qualitative study with empirical data and analysis from the current literature that focus on our three categories of questions: stress, weight discrimination and dietary restraint. This will help us to understand what is underneath the findings of our research. We are aware that qualitative and quantitative researches are two separate paradigms. However, we want to use the technical version, which views the two research strategies as compatible and therefore capable of being combined. Also according to Hammersley s classification of approaches to multi-strategy research, using the logic of triangulation will help us to interpret our findings obtained in the focus group interview through existing quantitative research, present in the literature (Bryman, 2004). This quantitative research uses a method that is consistent with the tradition of positivism where knowledge is measurable, repeatable and empirical (ibid) and will give us the opportunity to get a better understanding of the findings of our qualitative study and also to investigate them more deeply. 3.1 Literature search The selection of our literature The objective in the choice of the texts selected consisted of creating a platform of evidence to construct a theoretical framework, which we will use to discuss our findings obtained with the focus group interview. Twenty texts were chosen to supply the primary theoretical framework of our thesis and will also support our discussion. Through our literature assessment, we discovered that Rebecca Puhl (PhD) is a prominent scientist in the research concerning weight stigma, and its influence on emotional and physical health. Puhl is Director of Research and Weight Stigma Initiatives at the Rudd Center for Food Policy and Obesity at Yale University. She has published many recent articles focusing on identifying and coordinating research and policy attempts aimed at reducing weight bias. It therefore made sense to us to use 11

12 her literature on stigma of obesity. We also refer to the research of Kelly Brownell, the director of the Rudd Center at Yale University. Peter Muenning (MD, MPH) is an assistant professor of Health Policy and management at Columbia University. He is prominent in the research concerning socioeconomic disparities. Some of the most important texts selected are listed bellow. We needed recent texts about weight discrimination or stigma of obesity: We selected the review from Rebecca M.Puhl and Chelsea A. Heuer that has been published in 2008: The Stigma of Obesity: A Review and Update, and Puhl and Brownell (2001): Bias, Discrimination and Obesity, because the authors have included an extremely extensive quantity of research in their analysis and have reviewed all the recent and most compelling evidence to date on stigma and obesity. We also selected from WHO website a point of view from Lily O Hara (2006), titled The War on Obesity: A social Determinant of Health. This text is relevant to our topic because it follows our topic and argues between the weight-centered paradigm and the health at every size paradigm used in health promotion. It also gives evidence based on dieting and discrimination of body size. The text of Muenning published in the BioMed Central (2008), The Body Politic: The relationship Between Stigma and Obesity Associated Disease, also gave us good input on the cause of obesity and supported our idea that stigma-induced stress plays a role in the persistence of obesity. Texts related to low social status: A recent article of Alessandro Bartolomucci (2009): Metabolic Consequences and Vulnerability to Diet Induced Obesity in Male Mice under Chronic Social Stress as it includes various measures of physiological responses and metabolic consequences of social stress and because it supplies a model which we will argue parallels the present circumstances for overweight women with low social status. 12

13 On the same angle we used the text from Shively and Wallace (2001): Social Status, Social Stress and Fat Distribution in Primates for its great insight on stress and social status that is important to answer our research question and the article by Lemeshow et al (2008): Subjective Social Status in the School and Change in adiposity in Female Adolescents. Finally we used the review article by Lauren Lissner (1997): Psychosocial Aspects of Obesity: Individual and Societal Perspectives for its pertinent arguments on psychological consequences of obesity and dieting and also the place obese persons have in today s society. Texts related to stress and obesity: A text from Mary Dallman et al. (2003): Chronic Stress and Obesity: a New View of Comfort Food in order to discuss though her evidences the point that the effect of chronic stress on animal experiments applies also to humans. The text from Siervo (2009), The Contribution of Psychosocial Stress to the Obesity Epidemic, An Evolutionary approach for its relevance on our project and its precise description of the physiological and metabolic consequences of stress response. On a more sociological level, we also choose the text from Swinburn and Egger: The Runaway Weight Gain train: Too Many Accelerators, Not Enough Brakes published in BMJ, in September The authors made pertinent arguments about a series of vicious cycles that seems to perpetuate the obesity epidemic and challenge refers to weight management that will be a support a part of our discussion. It also relates on the weight discrimination and social status issue. Of more specific relevance to human, and especially on female eating behavior under stress: The study of Georgina Oliver (2000) Stress and Food Choice: A Laboratory Study as a part of the theoretical framework because it is an experiment on human eating behavior and shows the changes in eating behavior caused by 13

14 stress as well as which groups are vulnerable to unhealthy changes brought on by stress. It gives evidence that women eat more sweet/fatty food under stressful conditions, which is needed to discuss the findings of our research Assessment of the literature Pubmed (MESH database), WHO and Google Scholar have been used mainly for the literature search. The MeSH database has been used extensively during our bachelor education and we are accustomed to its search methods. We also used texts from our teachers as obesity and stress has been an extensive module of our Bachelor education. The literature search on Pubmed has been conducted in order to find research on effective, evidence based stress, psychosocial stress, overweight, obesity, dieting and weight loss strategies and stigmatization of obesity. Due to the extensive literature on our topic, we agreed that it was sufficient to narrow our search to free articles. We prioritized peer-reviewed articles and review articles. The research has been done in different steps as follow: 1 st step: (Stress AND Obesity), we found 80 articles and ten reviews. Eight texts were selected 2nd step: we searched for ((Stress AND Weight Loss) AND diet)) and we found five texts and two reviews but none was relevant to the topic. 3rd step, we searched ((Stress Psychological AND Diet) AND Obesity)). We found 12 texts and two reviews. One text was selected 4th step: Finally we searched for ((stress psychological AND eating AND Obesity) OR Overweight AND Emotions)). We found 96 texts and five reviews. Three texts were selected. 5 th Step: We searched for (Obesity AND Social Class): We found 175 texts and five reviews. One text was selected. 6 th Step: We searched for (((Social Dominance AND Women) OR Female AND Obesity) OR Dominance-Subordination))). We found 84 texts and 14

15 selected one. 7 th Step: We searched for (Social desirability AND Overweight). We found 88 texts, and four reviews. We selected one prospective cohort study article. Finally with Google Scholar and WHO, we selected from Yale University Public Health department website, a review from Rebecca Puhl and Chelsea Heuer: The Stigma of Obesity: A Review and Update (2008) for its strong level of evidence toward our topic. Another text The contribution of psychosocial stress to the obesity epidemic: an evolutionary approach has been downloaded from the National Institute of Health website and from WHO, searching for Stigma for obesity women, we selected a point of view from the Health Promotion Journal of Australia (2006) edited by Lily O Hara. From the 14 text selected total, we kept ten because of their content and evidence strength were relevant to answer the research question. 4. Theoretical framework 4.1 Stress and Obesity correlation Robert Sapolsky, professor of Biological Sciences and professor of Neurology and Neurological Sciences at Stanford University and a prominent researcher in stress and the brain, states that All vertebrates respond to stressful situations by releasing hormones, such as adrenalin and glucocorticoids, which instantaneously increase the animal's heart rate, blood pressure, and energy level (Shwartz, 2007). Two of the systems involved are the sympathetic nervous system and the hypothalamicpituitary-adrenal axis (HPA axis). This is an ancient response and the same hormones are secreted in fish, birds, and reptiles. Cytokines are also secreted and prepare the body for injury by enhancing blood clotting (Muennig, 2008). It is an adaptive response for most animals environments. It mobilizes energy and prepares the body for action. Blood flow is decreased to systems that are not immediately necessary for survival, such as the digestive system. The hormones are the same even when the causes of stress are purely psychological (Shwartz, 2007). 15

16 Psychological stress affects the endocrine system and modifies hormones in diverse ways, not yet fully understood (Shwartz, 2007). It affects the nervous system and the brain and many different organs. Chronic activation of the neuroendicrine system may promote energy conservation in the body that leads to a positive energy balance, and hypercortisolemia promotes adiposity (Siervo, 2009). Activation within the hypothalamic-pituitary-adrenal system and sympathetic nervous system modifies metabolism and appetite (ibid). Increased levels of corticosteroid affect insulin action on the liver and results in changes in metabolism, which promote gluconeogenesis and lipogenisis. The interaction between corticosteroids and insulin promote fat accumulation (ibid). These hormonal changes also increase visceral fat deposition, which may increase risk of CVD (ibid). It is because of this complexity and the extensive and dynamic action of stress hormones that stress is expressed physiologically, behaviorally, and emotionally. Graph A on Figure 1 shows that when exposed to social stress and fed a standard diet, weight gain among submissive mice coincided with weight loss among dominant mice. Figure 1A also shows that when exposed to a high fat diet, submissive mice gained dramatically more weight than dominant mice. When put on a standard diet, socially dominant mice had a negative energy balance while subordinate mice had a positive energy balance under induced social stress (figure 1 A). While both groups responded with hyperphagia (figure 1B), the submissive mice had a higher cortisol response (Bartolomucci et al., 2009). These results were predominantly attributed to differences in physical activity rather than eating behavior. Data from social stress and animal experiments are accepted as a valid model for stress induced weight gain in humans (Dallman et al., 2003). 16

17 QuickTime et un décompresseur sont requis pour visionner cette image. QuickTime et un décompresseur sont requis pour visionner cette image. Figure 1: Overview of the metabolic effects induced by chronic psychosocial stress. The graph shows changes (versus the mean value of the control group-housed mice) for body weight changes and food intake under either standard or high fat diet (Bartolomucci et al, 2009, page 5). Research involving macaques living in long term, stable groups also showed chronic stress and higher energy intake among subordinates (Wilson et al., 2008). Subordinates continued eating both day and night while dominants restricted consumption to the daytime. Dysregulation of the HPA axis and reduced glucocorticoid negative feedback was also found in these subordinate macaques due to chronic psychological stress (ibid). 4.2 Stigma of obesity: the social subordination of women Fat bias and discrimination are pervasive in western societies. In a review of a systematic literature search of articles published between 2000 and 2008 that related to discrimination and prejudice of overweight, Puhl and Heuer (2009) found that weight related prejudice is present in work settings, health care, interpersonal relationships and education. Stereotypes suggest that overweight and obese people 17

18 are lazy, unmotivated, less competent, lacking in self-discipline and sloppy. Overweight and obese individuals are victim to social injustice, unfair treatment, and impaired quality of life as a result of substantial disadvantages and stigma, especially for women (ibid). The affects of these stereotypes are found at every stage of life for overweight individuals. They receive punishment even from those very closest to them. Even controlling for income and grades, parents provide less college support for their overweight children than for their thin children (Puhl and Brownell, 2001). In general overweight employees receive less pay and fewer promotional opportunities than thin people in the same job position. However, discrimination is found more predominantly among women than men, and women were 16 times more likely to report weight discrimination in employment than men (Puhl and Heuer, 2009).. The European Union conducted a study that showed that a 10% increase in the average BMI reduced the hourly wages of females by 3.3% compared to 1.9% in men. Obese individuals are also penalized in health care. 24% of nurses said they are repulsed by obese people, and coverage for obesity treatment is typically explicitly denied by insurance companies (Puhl and Brownell, 2001). Furthermore, 68% of women with a BMI over 55 reported that they delayed seeking health care because of their weight (Puhl and Heuer, 2009). Overweight individuals are perceived as being personally responsible for their condition. General physicians in France ranked noncompliance and lack of motivation as the most important barriers to treating their obese patients (ibid). This prejudice takes a toll on psychological well being. Overweight women who have had more frequent experiences with discrimination reported more depressive symptoms, and stigmatization is positively correlated with low self esteem (ibid). Obese persons experience a high level of stress, and this stress may be induced by discrimination of overweight and obese people, due to the negative perception of their body image in comparison with thinner individuals (Muenning, 2008). In western societies, being lean is often associated with beauty, success and self control, while overweight and obesity are considered as undesirable and given other negative attributes (Lissner, 1997). Shively and Wallace (2001) showed that female monkeys low on the social status hierarchy, or subordinates, are physiologically different from dominants, and they 18

19 hypersecrete cortisol under stress. Subordinates were more susceptible to coronary artery atherosclerosis and the metabolic syndrome and store more abdominal fat than dominants. They hypothesized that social subordination leads similarly to stress in human beings. They explained that: like monkeys, human primates with low social status have relatively little control over their lives, and low control is a source of chronic stress that could engender physiological responses that are deleterious to health (Ibid 206). Research has shown that low subjective status predicts weight gain in humans in a way similar to submissive mice and monkeys. Low subjective social status in adolescent girls was also found to predict weight gain girls age reported their perception of their social standing relative to their peers (Lemeshow et al., 2008). Those who placed themselves low in social status were 69% more likely to gain a two unit increase in BMI. Age, race/ethnicity, baseline BMI, diet, television viewing, depression, global and social self-esteem, menarche, height growth, mother s BMI, and pretax household income were all controlled for (ibid). 4.3 Stress, eating behavior and weight gain Recent research has increased the understanding of the way stress changes quantity and quality of diet. Many correlations between stress and overeating have been observed especially in women (Oliver, 2000). Stress has been shown to increase desire for foods high is fat and sugar. Women are more interested in snack type foods, rather than meal food such as meat and vegetables while stressed (ibid). Another study showed women under stress (with measured increase in cortisol) reported lower postprandial satiety and increased energy intake compared to the rested controls. Increased energy intake coincided with decreased reward signaling and sensitivity (Born et al., 2009). Because reactions related to eating behavior are inconsistent, research has focused on identifying which groups of individuals have the highest risk of weight gain. Scientists are beginning to sort out what type of people have an increased appetite and are therefore vulnerable to positive energy balance while stressed. There is 19

20 evidence that women are more likely to show a marked hyperphagic response to stress which results in an increase in energy intake, in contrast to men, who often eat less (Oliver, 2000). One study showed that participants high on anxiety and low on social support were more likely to show a hyperphagic response (ibid). Restrained eaters also consume more energy and fat as a stress response (ibid). Other studies have revealed that taste and perception of sweetness change under stressful stimuli, depending on traits of arousability, affective valance, and dominance (ibid). Social status also has an influence (ibid). Emotional eaters are more likely to be female (ibid). Research done on rats has shown that stress can modify neuroendicrine action and increase energy intake in subordinates, which results in weight gain. Higher levels of corticosterone and glucocorticoid were found among subordinate rats than in dominants (Tamashiro et al., 2007). Elevated corticosterone has been linked to preference for energy dense foods (Wilson et al., 2008). Induced weight gain before hierarchy formation also predicted subsequent social status formation. Those most vulnerable to weight gain were more likely to be subordinate once the colony was formed (Tamashiro et al., 2007) Physiological function of changes in food choices One explanation for the function of preference of snack type food to meal type food is that energy dense snacks are easier to ingest and digest when under sympathetic stimulation (Oliver, 2000). Sympathetic stimulation causes hormones to be secreted, which prepare animals for fight or flight. Blood is drawn away from the digestive system to parts necessary to perform the physical acts necessary for immediate survival (Shwartz, 2007). Considering the environment of our ancient ancestors, it makes sense that high energy, easily digested foods would be appropriate for stressful situations. Another explanation of the function of changes in food choice is that it actually counteracts neurohormonal changes caused by stress. Highly palatable foods may 20