Stress and eating behaviors in children and adolescents: Systematic review and meta-analysis

Abstract

It is well established that stress is linked to changes in eating behaviors. Research using adult populations has shown that stress is associated with both increases and decreases in the amount and type of food consumed. However, due to a lack of research reviews, the relationship between stress and eating behaviors in children is unclear. This systematic research review and meta-analysis aimed to identify whether stress is associated with healthy and unhealthy eating behaviors in children aged 8–18 years. Studies were included in the review if they measured stress and included a measure of food consumption. All unique studies retrieved (N = 28,070) were assessed for their eligibility at title, abstract and full text levels. A total of 13 studies were included in the final review and data were analysed using Comprehensive Meta-Analysis. Using random-effects modelling, overall stress was not associated with a change in overall eating behaviors. However, additional analyses indicated stress was associated with unhealthy eating behaviors in both younger (Hedge's g = 0.283, p < 0.001) and older (Hedge's g = 0.274, p = 0.001) children. In contrast, stress was not associated with healthy eating behaviors in younger children (Hedge's g = 0.093, p = 0.156), but was negatively associated with healthy eating behaviors in older children (Hedge's g = −0.384, p < 0.001). The current findings are concerning as they suggest the impact of stress on unhealthy eating may begin as early as 8 or 9 years old. Future research ought to investigate further the role of psychological, behavioral and endocrine factors in the development of stress-related eating in children.

Introduction

The experience of stress has been theorized to influence health outcomes via two different pathways; a direct and an indirect pathway (Contrada and Baum, 2011, O'Connor et al., 2008). Experiencing a stressor directly influences the activation of the hypothalamic-pituitary-adrenal axis which increases circulating glucocorticoids (such as cortisol) and adrenocorticotropic hormones in the body (Ulrich-Lai & Herman, 2009). As such, prolonged experience of stress has been directly associated with detrimental health outcomes, such as increased risk of cardiovascular disease (Kivimäki et al., 2006), poorer mental health (Staufenbiel, Penninx, Spijker, Elzinga, & van Rossum, 2013) and accelerated disease progression (Cohen, Janicki-Deverts, & Miller, 2007).

Indirectly, stress is also thought to influence health outcomes by influencing an individual's engagement with particular behaviors. For example, experiencing a stressor may lead to deviations in normal health behaviors, such as eating habits, which in turn can increase the likelihood of poorer health (O'Connor and Conner, 2011, Torres and Nowson, 2007). Research has indicated that this indirect pathway between stress and health is particularly evident in adult populations. For example, increased experience of stress has been associated with an increase in the consumption of high calorie foods (O'Connor and O'Connor, 2004, Tryon et al., 2013). Stress has also been linked to an increase in consumption of between-meal snacks and reduced consumption of low calorie high nutrient foods like fruit and vegetables (Mikolajczyk et al., 2009, O'Connor et al., 2008). These stress related eating behaviors can have deleterious effects on health by increasing body adiposity (Steptoe & Wardle, 2005), particularly in abdominal areas (Björntorp & Rosmond, 2000) and subsequently heighten the risk of becoming overweight or obese (Berridge, Ho, Richard, & DiFeliceantonio, 2010).

It is through this pathway that stress is thought to contribute (at least partially) to the increased prevalence of childhood obesity (Pervanidou & Chrousos, 2016). Identifying the types of health behaviors children and adolescents engage in is important within this critical age, because these behaviors can translate to habits which continue into adulthood (Mikkilä, Räsänen, Raitakari, Pietinen, & Viikari, 2005). The period spanning from childhood to adolescence is considered to be critical, with many childhood behaviors becoming adult behaviors (Alberga, Sigal, Goldfield, Prud'Homme, & Kenny, 2012). This is particularly true for poorer dietary habits established in childhood, with such behaviors often staying with an individual as they become older (Mikkilä et al., 2005). It therefore remains paramount to understand factors which may influence eating behaviors in children to ensure more positive habits are established in early adolescence, to foster better health for children as they become adults (Todd, Street, Ziviani, Byrne, & Hills, 2015). Although the relationship between stress and eating behaviors in adults is fairly well established (see Greeno and Wing, 1994, O'Connor and Conner, 2011), the influence of stress on eating habits in children and adolescents is less clear.

Moreover, a number of moderators of the stress-eating relationship have been identified in the adult literature (cf., O'Connor & Conner, 2011). Stress has been found to differentially impact healthy compared to unhealthy food intake. For example, Grunberg and Straub (1992) demonstrated that when stressed, women were more likely to select foods high in calories (and fat) and Oliver, Wardle, and Gibson (2000) found changes in consumption of sweet high-fat foods and more energy dense foods. Similarly, O'Connor et al. (2008) showed that daily stressors were associated with increased consumption of high fat/sugar snacks and with a reduction in main meals and vegetable consumption. Taken together, these results suggest that individuals, when stressed, shift their preference to more palatable and energy dense snack foods, which are less healthy and higher in fat. Therefore, an aim of the current meta-analysis was to explore the extent to which type of eating behavior (healthy versus unhealthy) moderated the stress-eating relationship in children.

The effect of age was also explored to compare the effects of stress on eating behaviors between younger (8–12 years old) and older (13–18 years old) children. These age bands were established based on average age of puberty onset which is typically around the age of 13 for boys and 12 for girls (Vizmanos et al., 2001, Wohlfahrt-Veje et al., 2016). As children progress into adolescence, they are given increased autonomy over their own eating behaviors (Bassett, Chapman, & Beagan, 2008) and as such may find that their eating behaviors are more influenced by stress compared to younger children. Therefore, we explored the effects of age on the stress-eating relationship. Finally, given the effects of stress on eating behavior are often more frequently observed in female samples (O'Connor & Conner, 2011), we also investigated the moderating effects of sex.

To summarise, the aim of this review was to quantify the relationship between stress and eating behaviors in children and adolescents between the ages of 8–18. More specifically, this review aimed to ascertain whether stress was differentially associated with healthy and unhealthy eating behaviors within this age group. Finally this review aimed to explore whether the relationship between stress and eating behaviors (specifically healthy and unhealthy) was similar in younger children (8–12 years old) and in adolescents (13–18 years old) and in males and females.