The Acute Stress-Hedonic Consumption Relationship: The Moderating Role of Individual Differences in Consumer Life History Strategies and Optimism

The Acute Stress-Hedonic Consumption Relationship: The

Moderating Role of Individual Differences in Consumer Life

History Strategies and Optimism

Faculty of Economic and Business, University of Groningen EBM217A20 Master’s Thesis Marketing Management

Prof. Dr. Bob M. Fennis May 7, 2021

Abstract

Multiple studies found that acute stress increases hedonic consumption, while other studies found the opposite or did not find an effect at all. This study tries to explain the appointed opposite results by investigating the possible moderators: life history strategy (LHS) and optimism. This is done with an online experiment. Participants were randomly assigned to read an article either about coming rough economic times (high stress) or meditation (low stress). Afterwards they were asked to indicate their willingness to pay for a range of products, followed by answering questions to assess their life history strategy and optimism. Fast life history individuals are more focused on short-term and favour instant gratification, while slow life history individuals are the opposite. It was expected that stress increases hedonic consumption for fast LHS consumers compared to slow LHS consumers. Secondly, it was expected that stress decreases hedonic consumption for optimistic consumers (optimists have more positive expectations of the future than pessimists), compared to pessimistic consumers, since optimists have more effective coping mechanisms and are less vulnerable to external eating. These expectations were not shown in the results of this study. For future research, it is recommended, among others, to have food available for the participants and use independent scales assessing optimism and pessimism.

The Acute Stress-Hedonic Consumption Relationship: The Moderating Role of Individual

Differences in Consumer Life History Strategies and Optimism 4

Stress and Hedonic Consumption 5

Stress, Hedonic Consumption and Fast vs. Slow LHS 7

Stress, Hedonic Consumption and Optimism 9

Method 11

Participants and Design 11

Procedure and Measures 11

Results 15

Preliminary Analyses 15

Target Analysis LHS 16

Target Analysis Optimism 16

Discussion 17

Limitations and Future Research Directions 19

References 22 Appendix 27 Appendix A 27 Appendix B 46 Appendix C 48 Appendix D 49 Appendix E 50 Appendix F 51

The Acute Stress-Hedonic Consumption Relationship: The Moderating Role of Individual Differences in Consumer Life History Strategies and Optimism

The world is transforming into a place in which obesity and overweight are becoming more and more common. Worldwide, more than 1.9 billion adults were overweight in 2016, 650 million of them were even obese and these skyrocketing numbers do not seem to decrease

anytime soon (World Health Organization, 2020a). Over 2.8 million people die yearly because of being overweight or obese. You would almost expect being overweight is out of people’s

control, but nothing could be further from the truth. Overweight often results from consuming too much caloric food; high in sugars and fat and a decrease in physical activity (World Health Organization, 2020a).

The current global COVID-19 pandemic forces humanity to face the dangers of obesity. Obese people have a higher chance on a more serious course of COVID-19; links between obese and hospitalisation as well as death have been found (World Health Organization, 2020b), which makes studying unhealthy eating (e.g. hedonic food consumption) and associated causative variables more relevant than ever. Since acute stress is much higher in the US than the world’s average and their obese numbers are one of the highest in the world (Fennis et al., 2021), acute stress seems to be an obvious causing variable of hedonic consumption (consumption of high palatable and energy dense food (Boggiano et al., 2015)). However, studies to the causal relationship between acute stress and hedonic food consumption show diverse results, which might be caused by (a) moderator(s). Fennis et al. (2021) already discovered the moderating role of life history strategies (LHS) in the stress-hedonic consumption relationship. The aim of this study is to replicate the first experiment of Fennis et al. (2021) and investigate the moderating role of differences in optimism across individuals in order to provide an explanation for the prior diverse results.

The main research question in this study is, therefore, “What is the effect of acute stress on hedonic food consumption?”

Indicating the following sub questions:

● Do individual differences in LHS moderate the stress-hedonic consumption relationship? ● Do individual differences in optimism moderate the stress-hedonic consumption

relationship?

To answer these research questions, an online experiment was conducted, where desired hedonic food consumption, LHS and optimism were measured, while acute stress was

manipulated.

Firstly, this study focuses on the existing literature. Afterwards, the method used is discussed, followed by an analysis of the obtained data. Lastly, findings of the study will be discussed and recommendations for future research will be given.

Stress and Hedonic Consumption

Acute stress is frequently studied as a factor that seems to influence hedonic food

consumption. Acute stress is experienced when one’s capabilities are subjectively surpassed by a certain demand, especially in uncertain and uncontrollable situations (Starcke & Brand, 2016). It is a certainty that people will encounter stress in their life, therefore one’s coping ability is of importance (Furman et al., 2018).

One often studied response to stress is hedonic food consumption. It is energy dense food, which means that it contains more calories per unit weight (Drewnowski, 1998). Thus, consuming hedonic food as reaction to stress instead of for metabolic need is alarming.

Studies done to the stress-hedonic consumption relationship show inconsistent results. Starting with the meta-analysis of Ferrer et al. (2020), their results indicate that stress can increase the desire to consume palatable, energy dense foods. In the study of Pool et al. (2015) induced stress led to participants putting more effort into smelling chocolate compared to participants in the stress-free condition, despite the odour being rated similar. So induced acute stress enlarges responsiveness to rewards. This shows that hedonic consumption is increased by acute stress, through the desire of scrumptious foods and/or experiencing the pleasantness of hedonic foods. To illustrate, Hsu and Raposa (2020) show that adolescents who experienced more stress than others desired palatable foods more and once they started eating it, they had difficulties to stop.This parallels another study, in which female participants in the stress condition ate less of the healthy and more of the unhealthy sweet choice compared to the unstressed female participants (Zellner et al., 2006).

However, later in a replication among men results showed that no-stress participants ate significantly more of the unhealthy food items than stress participants did (Zellner et al., 2007). This contradiction aligns with the review of Torres and Nowson (2007) where some studies show that acute stress increased palatable food consumption, while others showed no difference or even the opposite. More recent, a study did not find significant effects between negative emotions (among which stress) and food intake (restrained eaters excepted), which again confirms the unstable stress-hedonic consumption relationship (Evers et al., 2018).

Since existing literature provides inconsistent findings, it will not be surprising if at least one variable moderates the stress-hedonic consumption relationship. As indicated earlier, Fennis et al. (2021) already found a moderating variable: individual differences in consumer life history strategy.

Stress, Hedonic Consumption and Fast vs. Slow LHS

The Life History Theory states that all organisms have to choose, when dividing their energy and resources, between putting effort into their own development (somatic effort) and into reproduction (Laran & Salerno, 2012). Slow LHS individuals favour somatic effort, linked to later reproduction and delaying pleasure to increase rewards in the future. While fast LHS individuals, favour reproductive effort, linked to early reproduction and favouring instant gratification with associated (adverse) long-term outcomes. Whether one adopts slow or fast LHS depends on the circumstances one lives in. When growing up in tough circumstances (e.g. limited resources, intense rivalry) a fast LHS is evolutionary more beneficial as those individuals are uncertain of their future (Laran & Salerno, 2012).

Furthermore, fast LHS has been linked to consuming food whenever available, independent of energy needs (Maner et al., 2017). Not surprisingly, the results of their study showed a link between fast LHS and obesity in adults.

On top of that, research has shown that once experiencing stress, fast LHS individuals perform less effective coping strategies compared to slow LHS. Fast LHS individuals adopt a more reactive approach, while slow LHS individuals adopt more active control of behaviour (van der Linden et al., 2018).

The study of Fennis et al. (2021) was the first study to the moderating role of LHS in the inconclusive stress-hedonic consumption relationship. However it needs replication in order to be more conclusive. Besides, the used stress manipulation is questionable for inducing feelings of stress. Participants had to solve multiple mathematical issues by heart. In the high stress condition this had to be done under time pressure and feedback stating that they performed 10% worse than average was given. In the low stress condition participants could take as much time as needed per math issue and given feedback stated that they performed equally as the other

participants. Hence, this stress manipulation might have triggered feelings of frustration instead of feelings of stress. Therefore, this current study usedanother stress manipulation, to see if the found effects would be replicated by other types of stressors.

Nevertheless, the above discussed literature suggests a moderating role of LHS. Fast LHS individuals are more short-term focused, favour immediate gratification and cope with stress in a reactive and impulsive way, so it is likely that acute stress causes desire for hedonic food.

However, the opposite holds true for slow LHS individuals who are more focused on the long-term, delay gratification and cope with stress by active controlling behaviour, so experiencing stress is not likely for them to turn into a desire for hedonic food consumption. Therefore, it is hypothesized that:

H1: The impact of acute stress on desired hedonic consumption is increased for fast LHS

consumers compared to slow LHS consumers (see figure 1). Figure 1

Stress, Hedonic Consumption and Optimism

Another moderator that is expected to influence the stress-hedonic consumption relationship is optimism. Nes and Segerstrom (2006) came to the conclusion in their meta-analytic review that optimists have more effective coping strategies by trying to solve the

causing stressor, compared to pessimists who avoided the stressor. Besides, optimists, in contrast to pessimists, are able to adjust their coping strategy according to the stressor (Nes &

Segerstrom, 2006).

Optimistic individuals have more positive expectations of the future than pessimistic individuals (Nes & Segerstrom, 2006), therefore optimists are willing to put in more effort to reach wanted outcomes, contrary to pessimists. This might also be an explanation why research about optimism and eating behaviour shows that falling for bad eating habits and recapitulation are associated with pessimism (Kelloniemi et al., 2005). Thus, optimists might be willing to put more effort into changing behaviour in order to acquire health benefits in the future, while pessimists want to benefit from the unhealthy (but palatable) food now and do not consider possible future health. Not surprisingly, research shows that pessimists have more unhealthy eating habits and higher body mass index (BMI) compared to optimists (Kelloniemi et al., 2005).

Moreover, unhealthy eating can be caused by bad moods and situational pressure

(Kelloniemi et al., 2005). As stated before, optimists cope with negative emotions such as stress more effectively. Therefore, it can be expected that they are less prone to emotional (unhealthy) eating to deal with stress. Indeed, Robert et al. (2020) show that optimism is negatively related to emotional eating and their eating behaviour is least influenced by cues outside of bodily needs.

Summing up, optimists have effective, adjustable coping mechanisms for stress, are more willing to put effort into reaching desired goals (as future health), are less susceptible to

moderating role of individual differences in optimism between acute stress and hedonic food consumption has, to the author’s best knowledge, not been done yet. The purpose of this study is to fill that gap. It is expected that optimists can cope with acute stress effectively and will not desire hedonic food as a coping strategy. Contrary, for pessimistic consumers the opposite is expected, since they do not have effective coping strategies, are less focused on their future health and more vulnerable to emotional eating. So acute stress is probable to cause desire for hedonic food. Therefore, it is hypothesized that:

H2: The impact of acute stress on desired hedonic food consumption is decreased for optimistic

consumers compared to pessimistic consumers (see figure 2). Figure 2

Method

This research studied the moderating effects of both LHS and optimism, independently, in the acute stress-hedonic consumption relationship. To test this, an online experiment was conducted in week 13, 2021.

Participants and Design

Participants were recruited with convenience sampling by using the author’s network and social media. Gift cards were raffled as incentive to participate. 122 participants of ages ranging from 18 to 65 (M = 26.53 , SD = 7.70, 66.4% female, 57.4% Dutch) of various professions (63.1% students, 32% having a professional job, 3.3% unemployed) participated successfully in the online experiment. The between-subject design consisted of one manipulated factor (acute stress: high vs. low) and two measured moderators (LHS and optimism: continuous). Participants were randomly assigned to one of the stress conditions. This was done with the help of Qualtrics, while making sure an equal number of participants participated in both conditions. The second part of the experiment was exactly the same for every participant.

Procedure and Measures

The experiment started with a small introduction: introducing the researcher, what to expect, informing them about the confidentiality and the possibility to withdraw at any time. See Appendix A for the complete experiment outline. After reading the introduction, participants were asked to give consent to participate and could continue to the next page.

Starting with the independent variable, acute stress, which was manipulated by asking participants to carefully read a recent news article (Fennis, n.d.). The article in the high stress condition is about the coming tough times fueled by, among others, the COVID-19 pandemic, describing a man who lost his job and an upcoming, unavoidable economic downturn. The article

in the low stress condition guides readers through meditation to let them feel the immediate calming effects. Afterwards, participants were asked to write down how they felt in detail. It was indicated that the first part of the study was finished and they will proceed to the second part.

In the second part, participants had to visualize visiting their regular supermarket doing groceries and had to indicate their willingness to pay (WTP) on the presented 27 products. These products were food and non-food, hedonic (e.g. cookies) and utilitarian items (e.g. yogurt, toilet paper). The ratio spent on hedonic food products (cookies, ice cream, chocolate, chips and sweets) was used to calculate the WTP, in line with prior research (Fennis et al., 2021; Oliver et al., 2000). The ratio, the motivation to purchase hedonic food (M = .19 , SD = .06), was used as the main dependent variable. A high ratio indicate relatively higher WTP for hedonic food products than the non-hedonic products.

Thereafter, the manipulation check based on the mood measure of Acar-Burkay et al. (2014) using a 7-point Likert scale (1 = strongly disagree, 7 = strongly agree) takes place. In which participants had to think back about the article they read in the beginning of the experiment and fill in how they experienced reading it based on six items (e.g. how difficult, stressful). To assess their experienced acute stress only the item about stressfulness of reading the article was used. Higher scores indicate higher feelings of stress (M = 3.35, SD = 1.94).

Subsequently individual differences in LHS were measured as a continuous independent variable, using the K-SF-42 scale consisting of 42 items and seven subscales (Figueredo et al., 2017). Participants had to fill in statements on a 7-point Likert scale (1 = strongly disagree, 7 = strongly agree), such as “I find I usually learn something meaningful from a difficult situation” and “I contribute a great deal to the welfare and well-being of my friends these days”. Followed by indicating how much something occurred like “How much did your biological mother teach

you about life?” and occurs as “How much have your relatives shown your affection?” on a 4-point Likert scale (0 = not at all 3 = a lot). By combining the unstandardized scores an overall index was constructed, with lower scores indicating a faster LHS (M = 3.59, SD = 0.50). The K-SF-42 had good reliability (Cronbach’s α = .86). Standardized scores of the LHS measure were used for the target analysis, since the scale consists of different Likert-point scales.

Next, individual differences in optimism were measured as a continuous independent variable, using the Life Orientation Test-Revised (LOT-R) (Scheier et al., 1994). This scale consists of three positive formulated items as “I’m always optimistic about my future”, three negative formulated items as “If something can go wrong for me, it will” and four filler items. The ten items were answered on a 5-point Likert scale (0 = strongly disagree, 4 = strongly agree). LOT-R displayed good reliability (Cronbach’s α = .75). The scores on optimism were averaged, to construct general implications, with higher scores indicating optimism (M = 2.37, SD = 0.62). Similar to the original article of LOT-R, optimism and pessimism are seen as opposites of the same construct. Therefore, lower scores on the LOT-R measure indicate pessimism.

Then, participants’ subjective socioeconomic status (SES) was measured, to ensure the found results for LHS were not caused by individual differences in SES. SES was measured using the scale developed by Griskevicius et al. (2011). With items as “I have enough money to buy things I want” using a 9-point Likert scale (1 = Totally disagree, 9 = Totally agree). The total scale consists of seven items, including one statement to only check the participant’s attention “I speak fluently Czechoslovak language”. The three items on someone’s current SES were used as covariate in the analysis and showed good internal consistency (Cronbach’s α = .71). Higher scores indicate a higher current SES (M = 5.72, SD = 1.52).

The experiment ended with multiple demographic questions, followed by thanking and debriefing the participant. Participants could leave their e-mail address if they were interested in the research and its results. The e-mail send to those participants can be found in Appendix B.

Results Preliminary Analyses

Randomisation was checked with multiple independent T-tests on different variables. See Appendix C for the syntax. The independent T-test did not reveal a significant difference

between both conditions regarding gender (t(120) = 0.315, p=.753) , age (t(120) = -0.620, p = .536), Dutch nationality (t(119.9) = -1.524, p = .130), LHS (t(120) = 0.861, p = .391) and

optimism (t(120)=-0.099, p = .922). Thus, these variables were equally and randomly distributed among experimental conditions. Both LHS and optimism are continuous independent variables, therefore multiple linear regression analyses using PROCESS (model 1) was used.

Firstly, the acute stress manipulation succeeded, since the article about the coming tough economic times induced significantly more stress (Mhigh stress = 4.62 , SDhigh stress = 1.68) than the

article guiding readers through meditation (Mlow stress = 2.00, SDlow stress = 1.11). This is confirmed

by a regression analysis using the manipulation check as dependent variable and the stress manipulation, LHS and the interaction of LHS with the manipulation as independent variables, resulted in a significant effect of the stress manipulation (β = 0.682, SE = .26, t(118) = 10.21, p < .001, all coefficients standardized).Whilst the effect of LHS (β = -0.050, SE = .46, t < 1) and the interaction effect (β = 0.168, SE = .64, t(118) = 1.73, n.s.) were not significant. The same was done for optimism, which only had a significant effect of the stress manipulation (β = 0.553, SE = 1.06, t(118) = 2.01, p < .05) as well. See Appendix D for the syntax. Therefore, the stress manipulation succeeded, and overall effects of LHS or optimism on feelings of stress caused by the task or different stress provoking of the task as function of LHS or optimism can be

Target Analysis LHS

The hypothesis that acute stress increases the desire for hedonic consumption for fast but not slow LHS consumers was tested with a multiple regression analysis. The ratio of WTP on hedonic foods was used as criterion and the stress manipulation (low vs. high, effects coded), LHS and its interaction were used as predictors. The analysis did not result in a significant interaction effect between acute stress and LHS on the desire to consume hedonic food (β = 0.02, SE = .03, t(118) = 0.63, n.s.), nor any other significant effects. See Appendix E for the

PROCESS output.

The main effect of acute stress on desire for hedonic consumption was not significant (β = -0.01, SE = .01, t(118) = -0.57, n.s.).

Including the current SES of participants as a covariate in the analysis did not affect the results.

Target Analysis Optimism

A multiple regression analysis was also used for the second hypothesis which states that acute stress decreases the desire for hedonic consumption for optimistic but not pessimistic consumers. The procedure was the same as for LHS. No significant interaction effect between acute stress and optimism on the desire to consume hedonic food (β = 0.01, SE = .02, t(118) = -0.55, n.s.) nor other significant effects were found. See Appendix F for the PROCESS output.

Discussion

The aim of this study was to investigate the inconsistent findings on the acute stress-hedonic food consumption relationship. This was done by introducing the role of individual differences in LHS and optimism among consumers. In line with Fennis et al. (2021) it was hypothesized that the impact of stress on desired hedonic food consumption is increased for fast LHS consumers, but not for slow LHS consumers. Besides, based on existing research, it was hypothesized that the impact of stress on desired hedonic food consumption is decreased for optimistic consumers, but not for pessimistic consumers. To test the hypotheses an online experiment was conducted.

The current study did not show that the stress-hedonic consumption relationship is influenced by LHS, which does not support the first hypothesis. Fast LHS consumers did not show a greater desire for hedonic food consumption after experiencing acute stress than slow LHS consumers. It counters earlier research by Fennis et al. (2021) in which the moderating effect of LHS was found. Moreover, the current results are not in line with a study where it was found that fast LHS individuals consume food whenever available independent of their hunger (Maner et al., 2017). However, this can be explained by the experimental design, since

participants had to indicate their WTP for food only, if food was readily available, results might have been different.

Besides, the study tried to show that optimism decreases desired hedonic consumption when experiencing stress. Nevertheless, optimistic consumers did not desire hedonic food less than pessimistic consumers after experiencing stress, which does not support the second

hypothesis. This result counters prior research of Robert et al. (2020) who showed that optimists were less prone to emotional eating and eating caused by external cues. Furthermore, current results differentiate from a study which stated that pessimists want to benefit from hedonic food

now (Kelloniemi et al., 2005). The unexpected results of the current study might be explained by the hedonic food measure as well, since the food was not available at that exact moment.

Thus, the findings show that stress did not increase hedonic consumption for these consumers. Hence, no final explanation can be given why several studies do find the stress-hedonic consumption relationship (Ferrer et al., 2020; Zellner et al., 2006), while other studies do not (Oliver et al., 2000; Zellner et al., 2007). Despite the unexpected findings, the current study contributed to the research field, as such, that it gave more insights about the type of stressor that does not cause hedonic consumption. It used a different stress manipulation than was used in the research of Fennis et al. (2021), which, based on this research, did not seem to induce hedonic consumption. Besides, the current study introduced a possible factor, optimism, which was not studied for this relationship before. Even though optimism did not moderate the stress-hedonic consumption relationship in this case, the first step has been taken. This may lead to more research including optimism measures, since the literature strongly suggests that

differences in optimism may play a role in the studied relationship.

It is good to realize that this study does not give the conclusive answer to the question whether acute stress influences hedonic consumption or not. Multiple reasons can explain the absence of the studied relationship. The used stress manipulation might have affected the

research, it is possible that another stress manipulation would have caused hedonic consumption. The same applies to the LHS and optimism measures, the current used scales did show an

interaction effect, however, other validated scales might find an interaction effect.

Next, despite randomisation of the participants, it might be that the randomisation was not successful for unmeasured factors such as dietary restraint and satiety levels at the time of the experiment. This might have cancelled out the studied relationship.

Regardless of the fact that this research did not succeed to show the moderating role of LHS and optimism in the stress-hedonic consumption relationship, it is likely future research will, if the limitations discussed in the next paragraph will be taken into account. Even if it appears that fast LHS and pessimistic consumers seem to be vulnerable to the relationship, there is no need to panic for these consumers. Research has shown that fast LHS consumers are also more likely to react to information about the energy density of the food, resulting in less likelihood of consuming it (Fennis et al., 2021). Therefore, policymakers can think of requiring nudges, a warning of the high energy density on products. Besides, consumers can force

themselves to look at the caloric content of a product, and be thoughtful whether it is tolerable or not before consuming it.

Also for pessimists research did found tools preventing them from becoming a victim of their personality trait. Pessimists can become more optimistic with the help of cognitive therapy (Forgeard & Seligman, 2012). Moreover, the Penn Resiliency Program is very promising helping consumers to be more optimistic. In the program individuals learn to have more encouraging thoughts in difficult situations and be more aware of the correctness of their thoughts. This is likely to improve pessimists’ coping mechanism, resulting in less external eating in response to stress. As a result of the promising interventions, marketing managers (e.g. of mental health care centers and dietician practices) can promote the programs, since it benefits the consumers (e.g. better decision making, confidence and health).

Limitations and Future Research Directions

Several limitations of the study need to be mentioned, that also points to possible future research. Starting with the length of the experiment which might have had a negative impact on the attention and invested effort of the participants. The average time spent on the experiment

was about 20 minutes, which might have caused fatigue and lack of interest (Galesic & Bosnjak, 2009). Although the manipulation and hedonic consumption measure were in the beginning of the experiment, effort put into answering the LHS and optimism items could have been

significantly reduced. This could lead to low quality answers on the moderator scales, not representative of reality, whereby no moderating role was found. Therefore, future research should be mindful of the duration of the experiment. This can be done by using a shorter LHS scale, such as the mini-K (Figueredo et al., 2006), which only consists of 20 instead of 42 items. Besides, by only measuring one moderator, the experiment duration will be reduced as well, which is likely to increase the quality of the given answers.

Secondly, the desired hedonic food was measured by letting participants indicate their WTP for a range of products, without seeing or being able to consume the products. It is likely that this had an impact on the desire for hedonic food, as such that immediately available food would have caused more desire for hedonic food. This expectation is in line with found results in previous research, where people had stronger cravings for food in real life compared to food in virtual reality (van der Waal et al., 2021). Moreover, earlier research to the correlation between optimism and eating behaviour seem to be mostly based on readily available food (e.g.

Kelloniemi et al., 2005), which may play an important role to show the moderating role of optimism in the stress-hedonic food relationship. Therefore, it is suggested for future research to design an experiment in which participants can actually consume the food, as is done in for example the experiment of Zellner et al. (2006).

Lastly, future research could use a different scale to measure optimism. This study used the most often used LOT-R scale developed by Scheier et al. (1994). However, it received quite some criticism, since the creators of the scale assumed that it measures opposite poles (optimism

and pessimism) of the same dimension (Herzberg et al., 2006). Other research has shown that the scale consists of independent optimism and pessimism factors. Measuring optimism and

pessimism as unidimensional can create issues, since people can agree with optimistic and pessimistic items at the same time, cancelling out given answers. Therefore, it is recommended for future research to use different scales to measure optimism and pessimism, such as the

Optimism & Pessimism scale, which gives optimism and pessimism independent scores (Dember et al., 1989).

Although this study did not find any significant results, it provides a promising opening towards future research in the field of stress related hedonic consumption. The discussed literature strongly points towards an existing relationship moderated by several factors. By taking current limitations and future research recommendations into account, it is likely that a significant relationship will be found. Finding participating moderators will help creating useful interventions in order to reduce unhealthy eating habits and associated obesity numbers.

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Appendix Appendix A Experiment Outline Survey Flow

Introduction/cover story

---Page Break--- Main Part

High and Low Stress Conditions

This survey contains multiple parts and the first part of the survey is related with understanding how people read articles, what they are feeling and thinking about when reading.

You will read a recent article which appeared in a Sunday section of The Guardian. This article is selected because it has an ideal length for studies on reading. Please read the article very carefully and take your time to visualize the material as vividly as possible. After reading, you will be asked a few questions.

High Stress condition

Tough Times Ahead: The New Economics of the 21st _Century

By ALISON JAMESTON, Senior Writer --The Guardian

Five months ago Jonathan Pierce had a stable, well-paying job. Having earned a college degree, Jon was doing well at age 25. He even believed he was about to be promoted. Today, however, Jon is yet again standing in the dreary unemployment line downtown. “I didn’t think this could happen to me,” he mutters while shaking his head. “I have a college degree and I can’t even get a job interview, let alone a job. I’m facing foreclosure on my house, and I just don’t know where the money is going to come from.”

This depressing scene is not unique. If you thought the world had recovered from its latest recession and the economy is stable and growing, think again. Recent reports show that dark clouds are gathering on the horizon fast and a sharp economic downturn is imminent, fuelled by the crippling COVID-19 pandemic, the raging global trade war between the US, China and Europe, the Brexit, the immigration crisis in Europe, and the continuing instability in the Middle East.

Indeed, over the past year, unemployment lines have grown sharply again, both in the US as well as the EU. “The early numbers are staggering,” notes Oliver Windsor, the head of the EU

Economic Commission. And it’s not just blue-collar jobs like construction and food service that are being cut. It’s also white-collar jobs like management and office work that are being hit. Job

security appears to be a thing of the past, with more and more people losing their jobs almost overnight and being faced with the daily struggle of how to pay the bills, and make ends meet. According to Windsor, “the best-case scenario looks like the recession will return again. The worst-case scenario is a depression similar to that in the 1930s.” Unfortunately, there is little more the government can do to remedy the situation. As every economist knows, changing the interest rates might slow the bleeding, but it can’t fix the underlying structural problems. The impending economic crisis is only the beginning of a new reality faced by all of us. After decades of economic growth, experts agree that the U.S. and Europe are on the verge of an economic shift. “The economy of the 21st century is fundamentally different from that in the past,” explains Dr. Patricia Wharton, chair of the panel for EU Economic Stability. “The sad truth is that this generation is certain to be the first generation to do worse than their parents— and their children will likely be even worse off. The American Dream – as we know it – will no longer exist for our children and the same applies to European citizens. Rising oil prices, a housing bubble, skyrocketing energy prices, and a massive trade deficit only begin to scratch the surface of our economic problems.”

The fact that young adults should expect to have little economic advancement is only part of the imminent economic disaster. Skyrocketing worldwide population growth and scarcity of natural resources are both working together to transform the economy. To understand how these factors are changing life for all of us, Oliver Windsor, one of 80 leading scientists who contributed to the government report, reminds us of the basics: “There are literally billions of people out there competing with each other. And these people are not just competing for jobs. The truth is that they’re competing for food, water, and air.”

The underlying fact is that our planet simply cannot support tens of billions of people. While it may be difficult for some to even imagine that one might one day live in poverty, the world in the 21st century is so highly inter-connected that for many this reality is literally around the corner. Things that happen in China, India, and Africa have tremendous consequences for what happens in the rest of the world. And as necessities like safe food, drinkable water, and

breathable air become scarcer and expensive, the world as we know it will become a very different place.

Watching Jonathan Pierce wait in the unemployment line downtown, one can’t help but be reminded of the Great Depression—a time in history that most people only remember from their history classes. The images of the Depression are difficult to erase: Malnourished children begging for food, people standing in line for days just to get a slice of bread and a cup of soup, everyone struggling to feed themselves and their families. The sad truth for people like Jonathan Pierce and countless others is that losing a job is only the beginning. Tough times are ahead.

---Page Break--- Low Stress Condition

Peaceful Meadow Relaxation

By ALISON JAMESTON, Senior Writer --The Guardian

Present day living is full of hassles, chores and stressors. Yet, modern science has identified ways to overcome the burden of modern life, and regain a sense of calm relaxation that fosters balance and peace of mind. Research has shown that regular relaxation training delivers these benefits and so aids in promoting health and wellbeing. It allows you to take mental vacation to reduce stress and experience full body relaxation. The good news is that it does so immediately: there is no need for weeks of meditation to observe the calm and soothing effects, you will notice them immediately upon the first try-out. This is how it works:

“Take a moment to relax your body. Get comfortable. Notice how your body feels, and make some slight adjustments to increase your comfort. Take a deep breath in. Hold it… and breathe out, releasing tension.

Breathe in again, and as you exhale, allow your body to relax slightly. Continue to breathe slowly…deeply. As you visualize the following scene, let your body and mind become more and more relaxed with each moment.

Imagine yourself walking outdoors. You are walking through the trees...small aspens, their leaves moving in a slight breeze. The sun shines down warmly. You walk toward a clearing in the trees. As you come closer to the clearing, you see that it is a meadow. You walk out of the trees, into the meadow. Tall green grass blows gently... You are probably feeling a bit tired...It would be so nice to sit down in the grass.

Walk further into the meadow now...looking around... Imagine the meadow in your mind’s eye...what does the meadow look like? Find a place to sit. You might want to sit or lie down in the grass…perhaps you have a blanket with you that you can unroll over the soft grass and lie down. Feel the breeze caress your skin as you sit or lie down in the sun. It is a pleasant day…warm, but not hot…quiet and peaceful. Notice the sights around you. The grass, whispering…see the mix of meadow grasses, clover, wildflowers around you. Watch a small ladybug climb a blade of grass. Climbing up toward the top, pausing for a moment, and then flying away.

Imagine closing your eyes and listening to the sounds of the meadow. Hear birds singing…the breeze rustling the grass softly… Feel the sun on your face. Imagine turning your face up toward the sky, eyes closed, enjoying the warmth of the sun. Smell the grass…the wildflowers…the smell of the sun on the earth… Look around again to see the sights around you. Notice how the ground follows gentle contours of hills. See the blue sky above you…a few wispy clouds drifting slowly by.

See the trees at the edge of the meadow….The meadow is lush and green, a haven for birds and animals. As you watch, a deer peers out through the trees, and emerges to graze at the edge of the meadow. The deer raises its head to look at you, sniffing the breeze, and then turns, disappearing silently into the trees. Rest and luxuriate in this peaceful, beautiful meadow…. Notice the sights, sounds, and smells around you…. Feel the soft grass beneath you, the sun and breeze on your skin. Imagine all the details of this place.

Now it is time to leave the meadow and return to the present. Notice your surroundings. Feel the surface beneath you. Hear the sounds around you. Open your eyes to look around, re-orienting to the present. Take a moment to stretch your muscles and allow your body to reawaken. When you are ready, return to your usual activities, keeping with you a feeling of peace and calm.”

You can start with short relaxation sessions and with more experience, achieving relaxation will become easier and you will be able to relax for longer periods of time. Some people prefer to relax right before bed to help fall asleep. Others relax first thing in the morning to start the day refreshed and revitalized. Consider if there are times in the day when your energy is high or low. These can be ideal times to schedule in a brief relaxation session.

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---Page Break--- Dependent Variable - Willingness to Pay

Manipulation Check/Mood Measure (Acar-Burkay et al., 2014)

LOT-R: Scale for Optimism (Scheier et al., 1994)

Scale for Socioeconomic Status (Griskevicius et al., 2011)

Demographic Questions

Appendix B

E-mail Sent to Participants about Research and Results Dear participant,

In week 13 you participated in the experiment for my Master thesis. You indicated that you would like to know more about the research. First of all, thank you very much for

participating. In this mail I will briefly explain the research and its results.

You participated in a research to the effect of acute stress on hedonic food consumption and how this relationship is influenced by life history strategy and optimism. But what does this really mean?

Let’s start with acute stress. The experiment started with reading an article. Half of the participants read an article which guided the reader through meditation, while the other half read an article about coming though economic times. The second article was meant to induce acute stress.

With the research I wanted to investigate whether acute stress influenced the desire for hedonic food consumption. Hedonic food is highly tasty food, which contains a lot of calories.

The life history strategy means that when we are dividing our energy and resources, we have to choose between putting effort into our own development or into reproduction. People with a slower life history strategy prefer putting effort into their own development, linked to later reproduction and delaying pleasure. While people with a faster life history strategy prefer putting effort into reproduction, linked to early reproduction and favouring instant pleasure. It was expected that people with a fast life history strategy desired hedonic food more, when

experiencing acute stress, compared to those who have a slow life history strategy.

The results did not show this expected effect. There was no significant difference in desire for hedonic food between fast and slow life history individuals.

Another variable that was expected to play a role in the relationship between acute stress and hedonic food consumption was optimism. Optimists have more positive expectations of the future than pessimists. Research has shown that optimists cope with stress more effectively than pessimists and eat according to their nutritional needs, instead of according to external cues. Therefore, it was expected that optimistic individuals desired hedonic food less, when experiencing acute stress, compared to pessimistic individuals.

This expected effect was not shown in the results. There was no significant difference in desire for hedonic food between optimistic and pessimistic individuals.

In short, neither an effect of acute stress on hedonic food consumption, nor a moderating role of life history strategy or optimism was found in this current study.

If you have any questions or comments, you can contact me via email.

Again, thank you for your participation!

Appendix C

Syntax Independent T-tests for Randomisation Check DATASET ACTIVATE DataSet1.

T-TEST GROUPS=STRESS(0 1) /MISSING=ANALYSIS

/VARIABLES=Gender Age Nationality LHS_Average Optimism_Average /CRITERIA=CI(.95).

Appendix D

Syntax Regression Analysis for Manipulation Check REGRESSION

/MISSING LISTWISE

/STATISTICS COEFF OUTS R ANOVA /CRITERIA=PIN(.05) POUT(.10)

/NOORIGIN

/DEPENDENT Stressful_Manipulation_Check

Appendix E

Appendix F