The novel coronavirus disease (COVID-19) is an infectious respiratory virus, declared a global pandemic on 11th March 2020 (World Health Organization, 2020). The global pandemic of COVID-19 has caused radical changes in the structure of people’s daily routines in most of the countries around the world, including people`s food intake (Cancello, 2020; Haddad, 2020; Martin-Neuninger, 2020). Previous studies have suggested an increase in anxiety and depressive symptoms among the general population during the COVID-19 pandemic (Vindegaard & Benros, 2020). Such negative impacts on psychological health could provoke the overeating of unhealthy food and result in weight gain (Khalid, Williams, & Reynolds, 2016; Hootman, 2018; Fernanda et al., 2019; Moynihan et al., 2015). Recent research reported that many individuals report increased binge eating, overeating, using food to cope with Coronavirus stress, and unhealthy food intake during the COVID-19 pandemic (Ammar, 2020; Phillipou, 2020; Wang, 2020). Previous study has determined that university students lack adequate and balanced meals due to their separation from their families, insufficient funds, or lack of time and information about healthy nutrition (Yilmaz, Aslan, & Unal, 2020).
Previous research has found that overeating is a relative term. Short-term overeating is a common human habit associated with feasting and celebration. In traditional societies this does no harm and may well do considerable good by replenishing body fat stores in environmental conditions in which extreme seasonality imposes a feasting and fasting mode of survival. Overeating becomes a health risk when it sustained over long periods. The fundamentals of the energy balance equation dictate that long-term overeating will always lead to body fat storage and obesity (Prentice, 1992). Overeating this article studies refers to the consumption of an energy intake that is inappropriately large for a given energy expenditure (Prentice, 2001). Overeating is not only a direct cause of obesity and eating disorders, but also an important risk factor for internalization and externalization problems such as depression, anxiety, self-harm, and substance abuse (Striegel-Moore & Bulik, 2007). As we all know, diet is a key driver of health (Global Burden of Disease Group 2019) and well-being (Govindaraju, 2018; Marx, 2017), not only through the provision of nutrients which support health (including immune health) (Calder, 2020) or patterns of consumption which influence disease risk (Global Burden of Disease Group 2019), but also the social health benefits of shared meals (Fischler, 2011). In other countries, the COVID-19 pandemic and associated containment strategies are thought to have affect eating behaviour (Dou et al., 2020; Yang et al., 2021; Zhao et al., 2020). In Italy, which experienced a severe outbreak early in the COVID-19 pandemic, one survey found that around 53% of respondents reported eating more during lockdown and 19.5% reported weight gain (Scarmozzino, 2020). Another survey of adults in Poland, more than 40 % respondents reported eating more and 42 % respondents reported weight change (loss or gain) (Sidor, 2020). Aside from the society-wide impact of confinement on diet, loss of the sense of taste and smell is a common side effect in those who infected with COVID-19 (Parma, 2020), which may also affect dietary intake.
From a psychosocial perspective, the outbreak of the COVID-19 can be likened to an acute stressful or traumatic event, involving potential threat to self and close others’ survival. As such, COVID-19 can lead to the emergence of various sorts of psychological problems (Lima et al., 2020; Torales et al., 2020; Zheng, 2020). Individuals is different in their reaction propensity to experience negative life events. Whereas some react strongly to negligible life stressors; others seem to remain relatively calm even in the most adverse situations (Folkman, 1984). When confronted with challenge or environmental uncertainty (e. g. COVID-19 pandemic), one’s response is not arbitrary. In the recent literature, evolutionary-informed theories aimed to explain such individual differences have become more prevalent (Del Giudice, Ellis, & Shirtcliff, 2011; Ellis et al., 2011; Figueredo et al., 2006). One of those theories is the Life History (LH) theory, which was initially focused on explaining differences in reproductive strategies between species (Wilson, 1975). At the core of life history theory (LHT) is the appreciation for the enduring influence of information in early development being utilized as a forecast in service of meeting the environmental demands of later development (Ellis & Bjorklund, 2012; Mittal & Grikevicius, 2014). Life history strategies exist along a “slow” to “fast” continuum – terms that indicate the relative tempo of one’s development and reproduction (Ellis & Bjorklund, 2012). The fast strategy and the slow strategy constitute the two poles of the life history strategy continuum. The weighing result of the individual determines its position in the continuum, and leads to the formation of corresponding personality traits as the executive body, coordinating behavior and the environment to work together to complete the adaptation task (Geng et al., 2014). Slow strategists are characterized by stable relationships (kin, romantic, social exchange partners) and a propensity for long term planning, risk averseness, and prosocial behavior (Del Giudice & Belsky, 2011). Fast life histories are marked by the opposite pattern. Fast strategists accelerate development and develop an orientation toward succeeding in the here and now, so they are more inclined to enjoy the current pursuit of instant gratification. These include risk taking, short term decision making, and decreased the level of prosocial (Del Giudice & Belsky, 2011; Ellis et al., 2003; Simpson & Belsky, 2008). In other words, when individuals are facing the negative effect of the COVID-19 epidemic, individuals with a slow life history strategy will solve the problem in a more constructive way, while individuals with a fast life history strategy will do the opposite. Although food scarcity has been improved in the modern world, individuals with fast life history strategies may still be more prone to overeat, because fast life history strategies are associated with high levels of impulsivity and instant gratification, and delicious foods can satisfy an individual’s need for instant gratification (Luo et al., 2020). In addition, both cross-sectional and longitudinal studies found a positive association between fast life history strategies and addictive behavior such as smoking and alcohol abuse (Chang et al., 2019b; Lu & Chang, 2019), as well as problematic eating behaviors (Maner et al., 2017; Salmon, Figueredo & Woodburn, 2009). Maner et al. (2017) found that fast life history strategies, overeating and body mass index are three closely related variables in an online survey of 400 participants. Salmon et al. (2009) found that the fast life history strategy significantly predicted increased eating disorder symptoms. In other words, individuals with fast life history strategies during the COVID-19 epidemic may be more inclined to overeating.
Given this theoretical framework, the aim of the present study is to investigate whether the life history strategy of college students is significantly associated with overeating and examine the potential mediating and moderating mechanisms in this association.
1.1 Sense of control as a mediator
In examining the overeating, it is important to consider the possible mediators that may play a role in decreasing the levels of overeating. In particular, sense of control may be a subsequent consequence of different life history strategy as well as being an antecedent of overeating. Sense of control is a central construct in psychology, and describes a basic motivational variable shaping one’s adaption to life and coping with life stress. As Bandura (2001) observed, “among the mechanisms of personal agency, none is more central or pervasive than people’s beliefs in their capacity to exercise some measures to control their own functioning and environmental events” (p. 10). “Sense of control” refers to subjective perceived control, rather than the objective control of events themselves, and this quality has both state-specific and dispositional elements (Skinner, 1996). Sense of control is a psychological driving factor for behaviors related to life history strategies (Mittal, 2014). Previous study shows that sense of control is significantly related to life history strategies (Dodge, 1990), and the fluctuating changes and levels of the sense of control are the result of internal trade-offs in the individual's life history. Fast strategists often maintain their sense of control through irrational behaviors such as current squandering and instant gratification (Wright, 2013), while slow strategists tend to maintain and improve their sense of control by reducing risky behaviors (Frey, 2017).
While past studies have evidenced that sense of control predicts a diverse range of overeating, no studies to date have directly investigated the mediating role of sense of control in the association between life history strategy and overeating in college students. While past studies have evidenced that sense of control is the most salient aspect of overeating (Telch, 1998), and that this feature is more strongly associated with psychiatric symptomatology than the quantity of food consumed (Wolfe, 2009). In the fields of obesity and eating disorders, it has been found that the ability to inhibit control is important for the regulation of dietary behavior. For example, studies have found that low control ability can cause people to experience overeating symptoms (Brooks, 2012). Previous studies have shown that there is a negative correlation between sense of control and poor eating behavior (e.g., overeating). The higher the level of individual control, the higher the level of regulation of their overeating behavior (Lu, 2015; Wu, 2015; Zhu, 2013).
Given the uncertainty associated with the course of COVID-19, it stands to reason those students with low life history strategy may engage in more sense of control, which in turn may decrease their risk for overeating.
1.2 Coronavirus stress as a moderator
Although life history strategy may impact college students’ level of overeating through the mediating role of sense of control, and individuals with different life history strategies respond differently to stressors, not all college students with low life history strategy may engage in a high level of sense of control. One key buffering mechanism may be Coronavirus stress.
COVID-19 is a health threat identified as a significant stressor threatening the mental health and well-being of many individuals around the world (Bhuiyan et al. 2020; Brooks et al. 2020; Satici et al. 2020). It has been suggested that COVID-19 stress can trigger mild to severe levels of psychosocial problems, such as depression, somatization, and anxiety (Arslan & Yildirim, 2020; Bhuiyan et al. 2020; Gunnell et al. 2020; Satici et al. 2020). There is extensive evidence that stress undermines the individual’s sense of control (Fisher, 2015; Keinan, 2002; Wang, 2011). In Malinowski's research, for fishermen who feel higher stress, they have lower sense of control over life events (Case, 2010; Malinowski, 1954). This is because stress coping involves the control of attention, thinking, and emotions, and this process itself is a process of consuming sense of control (Muraven, 2000; Pan, 2017; Tan, 2012). Previous studies have found that for those who abstain from alcohol, the more stressful events they experience in a day, the more likely they are to break the rules (Muraven et al., 2005); and test stress will weaken the individual’s sense of control in the laboratory and real-world situations (Oaten & Cheng, 2005). Based on past researches, uncertainties triggered by the COVID-19 crisis might bring about adverse outcomes especially for individuals who have a low sense of control, including an increase in the likelihood of these individuals’ unhealthy behaviors (Zhu et al., 2020) (e.g., overeating). Thus, the relationship between life history strategy and sense of control may be diminished for college students with higher Coronavirus stress. In other words, when the level of college students' Coronavirus stress is low, as individuals’ life history strategies change from fast to slow, their sense of control will increase rapidly, in contrast, their sense of control increase slower.
In addition, the psychological impact of stress is reflected in the fact that stress can lead to changes in the individual’s cognition, emotions, and coping styles, thereby affecting food choices. These changes can occur alone or interact (Kandiah et al., 2006). Born et al. (2009) has found that subjects who experienced more stress pursued a richer taste experience than those in the control group who experienced less stress. This is in line with the view of escape theory. Central to escape theory is the notion of multiple levels of meaning, which are linked to multiple ways of being aware of oneself and one's activities (Baumeister, 1990a; Pennebaker, 1989; Vallacher & Wegner, 1987). In this view, the reason why an individual has overeating behavior in a stressful situation is there is a significant gap between the individual’s actual state and the ideal standards. In order to avoid the negative internal experience brought about by this gap, individuals shrink their attention to the negative stimulus in environment, and this effort to avoid unpleasant emotions by narrowing the cognitive range will weaken the usual inhibitions around food (Heatherton & Baumeister, 1991; Heatherton, Herman, & Polivy, 1991; Qi, 2019). In other words, overeating is a defense mechanism when individuals face stress. Based on previous researches, when the level of college students' Coronavirus stress is lower, as their sense of control increase, their levels of overeating tend to decline rapidly; when the level of college students' Coronavirus stress is higher, as their sense of control increase, their levels of overeating tend to decline slower. To date, no previous studies examined whether Coronavirus stress as a moderator in the indirect relation between life history strategy and overeating via sense of control.
1.3 Present study
The purposes of this research were twofold: (a) to test whether sense of control would mediate the relation between life history strategy and overeating in college students, and (b) to test whether the direct and indirect relations between life history strategy and overeating via sense of control were moderated by Coronavirus stress. The proposed model is illustrated in Fig. 1. Based on the review of literature, we posit the following hypotheses:
Hypothesis 1. Sense of control will mediate the relation between life history strategy and overeating.
Hypothesis 2. Coronavirus stress will moderate the direct and indirect relations between life history strategy and overeating via sense of control.